Estimating Due Date

Not to discount what you think at all because you know your body the best. But, subsequent pregnancies can make you think you are further along because you notice things sooner and you can also begin to show sooner (because your abdomen already 'knows' what to do when you are pregnant plus the fact that your muscles never really return to normal after a first pregnancy).

So, unless you have a really good idea when conception took place, an ultrasound may be the best way to determine where you are. It is possible to have some spotting or an 'irregular period' in pregnancy though, so this is a possibility. If this is the case, you can ask your doctor to calculate from your last 'normal' period (which would have been December, right?). Cycle length can also be a factor in determining your due date. It usually only changes things by a couple of days though. For example, my last period began on December 17 so that would put my due date (according to the doctor's pregnancy wheel) at September 24th. But, my cycles are longer than 28 days. They are 32 days. So, that changes my due date to September 27th. See, only a few days.

As time goes by, the doctor may be able to determine that you are further along in your pregnancy based on some factors like fundal measurements (when they use the tape measure on your belly) and the size of the baby.

In all this, you should really keep in mind that due dates are estimates. They can be wrong in either direction. For me, I never deliver before 41 weeks. Well, my daughter was born like one day before 41 weeks only because of an induction. My son was born just a couple days short of 42 weeks. It is when you go past the 42 week point that there can be concerns. So, when it comes time for your 'due date' just keep in mind that if you are doing well and your baby is doing well, there is no reason to interfere.

Congratulations on your pregnancy! I hope it is a blessed one. :)

1 mom found this helpful

Ultrasounds early are best. VERY early. When I got pregnant with my third I didn't even have periods yet. So they had to do an Ultrasound at 6 weeks and 10 weeks to know for sure. I wouldn't have them CHANGE your due date. Delivering two weeks early or even 3 is normal. BUT if you go over your due date they WILL induce you and then you are SOL. Keep it the way it is. I know you feel ready but the baby will come when he/she wants to and you don't want them inducing you early and then risking a c-section to get the the baby out. Most doctors don't even give you a full 2 weeks past your due date anymore. And the AVERAGE woman is pregnant for AT LEAST 40 weeks. If you are white it's more like 42 weeks. Sorry that's just how it is. My first one was 6 days after the due date that I had them move up 2 weeks. So he was almost 3 weeks "late" according to the due date based on my period. According to an EARLY ultrasound he was only 6 days late. So be careful about moving up a due date. Better to have time then to take that time away and force their hand.

By the way, the early ultrasound (usually at your 1st prenatal appt) is the most accurate one for determining the age of the baby and how far along you are. The later ones when the baby is bigger are not as precise. That's what my OBGYN told me.

Congrats,
L. :)

my friend had a full period after she got pregnant-- so it can happen.

also, you can have bleeding when the egg implants in the uterus. another possibility.

do you know when you had sex? or when you ovulated?...

hope you figure it out... i'm sure your doc will have some ideas too.

when the baby is done cooking, you'll go into labor. then you'll know for sure. due dates are just a guess anyway...

When I became pregnant with my 5th child, I had no idea when we conceived. They did a blood test to determine how far along I was. Turns out, I was only about 6 weeks along. So at my first visit, around 10 weeks, they did an ultrasound and confirmed the date that the blood test had indicated. I will offer that this last pregnancy was COMPLETELY different than the previous 4. I felt like it was a first time pregnancy all over again with everything being so new! Good luck!

Sonagram is the only true way. I was pregant with my last and thought I was 2 months max. I was 4.5 months along. I had light periods but since I had had issues before with my periods I was not concerned. Boy did I get a big suprize.

Can you pinpoint a conception date? That's the best way to find the EDD because using the first day of your LMP assumes you have a perfect, 28-day cycle during which you always ovulate on day 14 (actually not very common).
Many women report showing within days of taking a positive test on their second because they muscles and tendons are all still relaxed.

Now, its been awhile, so if I'm wrong, don't shoot me, LOL. I think you count 40 weeks from the first day of your last period (I think you can calculate this online, I'm not sure). But, when I was pregnant with my second, I felt so much bigger all the way through my pregnancy (I wore maternity clothes at 8 weeks *sigh*)

I think the ultrasound is the only "real" way to tell. However, those are subjective too. If your baby is big or small the due date can change. When you go for your checkups the doctor will measure your uterus and can tell you if you're measuring "correctly" for how far along you think you are. I'm pregnant with #2 and this pregnancy is TOTALLY different then my previous pregnancy. I showed earlier (about 12 weeks), am gaining less weight (hooray!) and and just having an easier time over all. Everyone says that each pregnancy is different, so it's hard to say what you "should" feel like. Congrats on #2 :)

hello i have a sister who had a period 6 months of her pregnancy i know of quite a few cases that had their periods the whole pregnancy.it isnt uncommon and never take a drs word totally for this.unfortunately an ultra sound may be necessary to determine this.K.

With my third, I wasn't sure when my last period was, becuase of the birth control I was using. OOPS! They did a series of three ultrasounds throughout my pregnancy to get the due date. My doctor thought I was farther along than the ultrasounds showed, but they are the determining factor. I delivered 3 weeks "early," and she was 7lbs. 11oz and beautiful. All of my children were at least 1 week early and all were over 7 lbs. I wouldn't worry too much about it, if they need to adjust the date, they will, but the baby will come when its good and ready. They won't let you go too long or come to soon, medicine has come to far for that now. congratulations and good luck.

You can go off date of conception if you are sure of it. Most people aren't, so most doctor's offices will use either the last menstural period, or ultrasound. An ultrasound done before week 10 is most accurate for dates.

Also, keep in mind that you will show much sooner with a second child.