Help!

Alright ladies I need some help here. I have a 6 month old baby after i had him I bled and all that then my period came back as normal. Fast forward a little bit .. anyway my last period was July 4th (happy independence day to me!🤣) So I just took a test on sunday 8-18 I watched it, I thought it was negative I went and got a drink and came back and there was a faint line. So obviously I started freaking out. So I took two more tests both negative. I'm so confused I am setting up an appointment with my doctor on Monday but has anyone else been through this? If so, were you pregnant or was it something else?