Any doctors here or anyone with a similar experience here??

So I’m 44 days late. My last cycle was my during my birthday July 3-6. My period is usually 3-4 days. It’s Sep. 15 and I still haven’t gotten one. I’ve officially missed 2 periods now. August & Sep. Throughout August & early Sep I’ve officially taken 3 pregnancy tests. All came back indisputably negative. Yesterday I took a blood test for pregnancy & this morning the results came back negative as well. I knew it was negative because I’ve been pregnant before and I’ve had no symptoms of pregnancy. Nothing is out of the ordinary & I feel completely normal everyday since my last period. What’s wrong with me? 🤔🤷🏾‍♀️ my sister said she recalls me telling her my period has done this in the past and missing periods/ having them late is pretty normal for me so I don’t usually freak out. But it’s been a minute since it’s been this bad. I don’t have any answers…what do Yal think?