Medical mystery!

Chelsea
Ok this is kind of lengthy. So on 12/1 I went to my regular dr to get a Hcg blood test bc I was 13 days late and I took 10 at home test that all came back negative. The Hcg blood test came back negative but something kept telling me that it wasn't right. So on 12/2 I went to my OBGYN and got a exam and she requested I do blood work to see when I would ovulate so we can start figuring out why I'm not conceiving. Well on 12/8 I got a positive ovulation test 😳 (at this point I'm like 20 days late) I went in that same day to get the results from my hormone blood test results(which was drawn on 12/2) they showed that I had ovulated prior to 12/2. When I showed my doctor that I got a positive ovulation test on 12/8 she couldn't understand how. She made me do another urine test bc my progesterone level fell in the category of early pregnancy or recent ovulation anyway the urine pregnancy test came back negative. She just didn't understand how. So she put a rush in another Hcg blood test for me and a ultrasound to see if I'm pregnant or not. She also told me to go home and do the baby dance. 😳 then today I started my cycle.  I'm so lost. How could I have a strong positive ovulation test the day be my roug AF showed up?
 
Has this happened to anyone?