Congrats! I too have a son and another due May 27th so we are pretty close on due dates!! My first I had NO issues at all. This one has been a really crazy pregnancy with tiredness, pains, etc. Anyway, luckily my hubby is a nurse and can tell me all the things I am going through. Your pain is likely the baby dropping (called lightening). Around 35-37 weeks the baby will drop lower in the pelvis and that is where the pain is likely coming from. I get it too and it has been REALLY uncomfortable. Like you, I have a high tolerance for pain. Went for my 37 week check up today and the doc confirmed that I had dropped since last week and that hubby's prediction of the pain was correct! hope that helps! Congrats again and hang in there! Just a couple more weeks!