Egads! I was similarly tortured by this decision in my mid 20’s. Some failed experiments in birth control resulted in unplanned pregnancies which I miscarried. Suddenly, I was clear that I wanted to have kids someday, but not knowing for sure that I could put it off indefinitely gave me a push to decide in favor of moving ahead more quickly.
The process of seeing that fertility wasn’t a guarantee took some years and wasn’t easy, but there is nothing like losing 3 pregnancies to push you towards wanting a successful one.
I went on to have a baby at age 33. It was nothing short of miraculous. I enjoyed the difficulties you describe here along with the indescribable joy that came with it. I was lucky to have another baby when I was 35, but the circumstances around that pregnancy were fraught with challenges. I would not change any of it for anything.
I’m sure my experience won’t help you with your decision. My only real advice would be to not spend too many years trying to decide only to find your window has closed should you decide to go ahead.
I wish you peace and happiness along the way.