Wow.
I knew a couple. He was over 6 feet tall and she was a little thing. Their first baby was enormous and he missed the birth by minutes. He showed up all excited about the birth of their first baby and she sat up and yelled at him "You are never touching me again!" They went on to have two more kids.
My first pregnancy was really hard -- I threw up for 8 months and the birth was hard -- and it took me more than a year to be willing to try again. When I intentionally got pregnant again, I began throwing up and remembered how hard the first pregnancy had been. I think I also had the flu. I told someone "I hope I am pregnant, because this is making me remember my first pregnancy. If I am not already pregnant, I may not have another baby. Ugh. I don't want to go through this again."
Hormonal birth control has potentially deadly side effects. Women by the millions take it anyway because the risks and side effects involved are less worse than having babies.
Please realize I was a very devoted mother, desperately wanted kids, and still have a strong relationship to my now adult sons. I was baby-crazy in my twenties. I have talked to lots of women over the years and many women a) do not want kids and never did and b) after having the first, took a long time to be willing to try again because it was such a dreadful experience.
Women don't do this because being born female makes us more virtuous (or some crap) than men. We do it because we have the equipment, thus it is ours to do. That's it.
Also, female or not, memory is state dependent. This is not specific to pregnancy. When I had a serious health crisis and was in constant excruciating pain for more than 3 years, I could CLEARLY remember the birth of my first child. Most of the time, I cannot. I am usually not miserable enough to have good access to those memory pathways.
Again, state dependent memory is not some gender based or pregnancy based weirdness. The inability to fully access traumatic memories likely has a protective function for the human race and it is extremely well known, not some "pregnant woman" anomaly.