Very confused.

I'm 5 months pp and have had one period since having my son, beginning 6th May - ending 11th May. My partner and I had unprotected sex on 23rd May and 3rd June.

10th June I started getting faint positive at home tests across multiple brands (FRER, Clearblue, Easycheck, Freedom, Baby4you) They darkened slightly over the next 9 days but never to a blazing BFP. I went to my Drs, got a blood test and the results the same day - negative, less than 1mIU/mL Tested that same night and the lines were the darkest so far but I thought okay cool, must be a chemical or something.

I was testing to follow the line fade since then and officially got my first negatives 2 days after my blood test, I tested one last time the day after that and again, nothing.

It's now been 5 days since my blood test and my partner and I have had unprotected sex twice during that time. I still haven't had any cramping, spotting or bleeding at all since my last period in May. It's now June 23rd. So I tested today cause, paranoid lol

I've gotten a faint line again on 2x FRER and 2x Clearblue ???

Make it make sense please Is there something else that could be causing them? I'm SO confused.