Advice please

Hi just wondered if anyone has been through anything similar and has any advice?? Me and partner have been trying for a by for about a year I had a mc at 7 weeks 10 months ago and 3 months ago I had pregnancy of unknown location that ended up as a mc .. i waited for my first period and started using opk which gave me my smiley face 15th and I am Due af tomorrow I took a pregnancy test on Tuesday afternoon and got the faintest positive but I didn't another test wed and Thursday morning all negative?? Could I be pregnanct?? Was the test faulty? Or could I of had a chemical? Any advice would be appreciated thank you x