Pregmate Test Strips - Need Advice

Hey all - brand new to TTC. Used opk tests and had sex 3 days before and day of positive test. I’m now 13 DPO and 1 day from when my cycle should start according to the app, but I usually get some spotting 2-3 days before my period really starts. I had some light spotting (TMI but only saw when I wiped, not even in my underwear at all) 2 days ago (11 DPO). I’ve been taking pregmate strips every couple days, and my strip this morning was very clearly BFN. My boobs are so sore so I know something is happening...any chance I could be pregnant even with a BFG this close to my missed period?