stumped 😪

Samantha
Okay so I have a regular cycle give or take 2 days (usually 31). I am now 5 days late. Definitely BD according to glow when I should it's our first cycle so I stocked up on OPKS and a thermometer even preseed (I know going overboard) for when AF came this month JUST IN CASE so we would be ready... 
BUT MY PERIOD IS LATE AND I KEEP GETTING BFN - with the exception of a faint positive yesterday evening. Even tested this am and nada. I have sore bbs light headaches and constantly want to eat. 
Trying not to overthink. I'm on CD 36 so any insight from other mamas who had a similar situation or someone with help would be awesome :-)Â