"Fresh" sperm?? Helppppp

I need some happy success stories to cheer me up.

My doctor has prescribed progesterone and told me to start baby aspirin and CoQ10 as well as prenatals.

I've been pregnant 4 times. First pregnancy was so incredibly normal that gave me my healthy baby boy. The next 3 however ended in miscarriage. All around 6-7 weeks. I've had so many tests done and everything came back normal.

The ONLY thing that has been different in the pregnancies was conceiving. First time getting pregnant we had sex every day maybe even twice a day. The other 3, we rarely have sex. Like maybe once or twice during my fertile window if I'm persistent enough (That's it's own problem but anyway..) Could the sperm be weak and not make a healthy baby since it's not "fresh"?

I'm really hoping for another baby but I cant deal with another loss.