Not Sure

I'm not sure what's going on with me. I took a pg test this morning and it was negative after 5 minutes. :( However, I took the test at about 5am (when I woke up and couldn't sleep...) and I was pretty blurry-eyed. When I looked at the test at 8am I could see a faint line. Was it an evap line or a faint bfp? It is 10pm on 15dpo and I still haven't gotten my period. And, I didn't have as many cramps today (although I didn't have any full on cramps before, just the pre-AF mini cramps).

The question of the night is: do I take my progesterone supplement tonight? Usually my period starts about 12-13dpo while I am still taking the supplement. I know that if I do happen to be pg, I will need to be on progesterone support. I have an apt with my obgyn tomorrow morning so he can confirm with a blood test if AF hasn't shown by that time. I am leaning toward taking the prog. tonight, just in case... I guess I would rather err on the side of cautious than do anything that could jeopardize m/c a possible bean.