

Not sure about the US but where I live, all medical records need to be stored for thirty years, mostly so you have legal protection in case complications arise.
Imagine that a woman has an abortion, then years later she is pregnant again, this time with a child she wants to keep. She has a miscarriage and tries to sue the abortion clinic because she thinks they permanently damaged something during the abortion.
Also in case someone claims that a medical procedure was performed against their will or they were not informed about the risks.
And this works both ways. Because the clinics (and also all other medical professionals like midwives) must keep those records, the patients can demand them to be used as evidence to back up their claim.
If it is because you’ve never asked: not at all.
If he actively refuses to talk about it: at least a bit weird.