I am not sure what to think, just worried

I am 103days late for my period, I have taken 10 pregnancy test 2 Came back positive and 8 negative, had a blood test which came back normal, doctors request and ultrasound to check my ovaries but doesn’t know when the appointment will be because of the pandemic

This is the first time every I have missed a period this long, it normally every 30days like clockwork

Even with my previous pregnancies once I had my first period back they went like clockwork But this time it hasn’t

I been feeling sick, back pain started and looking blotted,

I just don’t know what to think? It’s driving me nuts not knowing

When I researched it their is rare case very impossible but it when women missed periods after and after, test negative on pregnancy test and blood test but are still pregnant

I been having unprotected sex so now their a chance

I have a ultrasound appointment coming but is delayed due to the pandemic

Any one got advice or been though this their self