Worried

I have 3 kids, all who were born full term. My youngest just turned 4. I've been with my fiancé for a year and a half now, and we weren't trying for a baby. We had a pregnancy scare in October (i was on birth control but had a steady period every month). But in October and December I didn't have a period at all. My doctor says I didn't ovulate. I'm 28. I've never missed a period unless I was pregnant. I'm worried that that was my body telling me "nope, no more babies". After our pregnancy scare we decided to try for a baby together. But uterine problems is in my genetics. My mother had to have a hysterectomy at the age of 32 because her periods were so bad she literally couldn't get out of bed. I'm terrified because mine are almost there.

Is randomly not ovulating normal? Or is it just me?