Speak to your OB about it.
I have heard of women getting pregnant even if not getting their period yet and breastfeeding. I got pregnant once, while breastfeeding...but I was having my periods. But I miscarried.
Try and research it online, do a Google search on the subject.
My OB/GYN recommends not breastfeeding while pregnant, because it can cause contractions. Although, I know women who still breastfeed while pregnant. I did that too... when I was pregnant that time... but by then my daughter was already in the process of self-weaning.
Your daughter is still actively breastfeeding and that's nice. It's great you are still doing this. With my daughter, I let her self-wean and she did, and she was about 2.5 years old then.
It's really up to you... but also you should get a professional advice about it, with your OB/GYN. That is the best and most conclusive advice you will get... and in light of your current health status, and about your periods.
each woman is different. If you are in no rush to conceive again... you can just let your daughter "self-wean" when she is ready. Extended breastfeeding still has many benefits for a child. And, then you can plan when to have your next child...but not rushing it, or having to do it "now."
I let both my kids self-wean. It was just the way I felt was best....and it was a natural process. My Hubby also was so proud of this.
If you are still wanting to breastfeed, and obviously your daughter is still nursing well... then just keep going. Follow your heart. A baby is only young once... and extended breastfeeding is fine. Lots of child experts support it, and do it for their own kids too.
You seem torn about weaning... I would not 'force' yourself or your daughter to do it, if you are not ready yet. Your girl does not seem ready yet. ?
But all the best in what you decide... I know it is not an easy decision. Follow your heart.
Take care,
Susan