confused please help!

so i took several test 5 days ago and they were all faint positives. and then i tested 3 days ago and all were negative (all same brand) and then i got my period the same day. heavy(ish) and i assumed it was a chemical.

well my boobs have been hurting like crazy so i said why not and took a test today. and it came out positive. and it wasn’t FMU, so not dark but darker than any of the test i’ve taken so far. i’m still bleeding (lighter now) and i’m beyond confused.

has ANYONE experienced this? one of my friends said it was possibly the vanishing twin syndrome. but does it happen this early?