False Positive, I think... 😐

Hello Support Ladies... I had a BFP with a First Response Digital last Thursday. 😆 Then I took two additional test that night- FRER-BFN and another digital that displayed a question mark. I decided that maybe my levels weren't concentrated enough. The next morning I used my FMU on a Clearblue Digital that read "Not Pregnant"... a few hours later I tried again with "Not Pregnant". Feeling very confused and upset I went to urgent care for a blood and urine test. The urine test came back negative and I'll be getting the blood results on Monday. I took another test last night, two days after my BFP and the day AF is due and still negative, one this morning and negative again (both were first response)  I'm feeling SO upset and confused. AF is now a day late. Has this happened to anyone? I've read about chemical pregnancy, but would I be bleeding already? Lastly, do you think it's possible that I am pregnant? If so should I be concerned that my levels don't seem to be increasing?.. Help :(