I got my period when I was 11 y.o. I am now 23 a

and my period has come every month on time since then. September of 2020 I went the whole month without a period and then it came two weeks into October. I took so many pregnancy test. I couldn’t understand why or what was wrong. My doctor did an ultrasound for cyst and he said everything seemed normal. It is now March and it’s happening again. I tested when I was 6 days late and when I was 10 days late all negative. I’m not going on being 20 days late.

Idk what wrong with my body but something just doesn’t feel right. & no I don’t think it’s stress because I’ve been through a lot and my period still showed up.

If I might add. I still have cramps everyday like it’s coming and it doesn’t show. Sometimes pretty painful