12 date late

Hello!

I have a little 16mo boy that I’m still breastfeeding, I’ve had normal periods since I was 6months pp, so 9 very regular cycles, but this month my period didn’t show, I’ve tested twice, once a week ago, and the second time yesterday, and both test were negative. We aren’t exactly trying but haven’t been super careful either. I’ll get an appointment with my gynecologist, but I was wondering if this has happened to anyone. I wonder if it’s just late because of breastfeeding, or I ovulated late, or if I could be pregnant but ovulated late and that’s why tests are negative. I know the best is to talk with my doctor, but I was wondering if this happened to anybody and what it was at the end :)

Thank you!