Faint positive progressing/chemical pregnancy question

So I’m unsure if I’m having a chemical pregnancy or not. I got a faint positive with FMU 6 days ago. Tested throughout the day that same day and the rest of my tests were negative. 3 days later, I tested (not fmu) around 1 pm and it was negative. The next day, Friday morning, I tested with FMU and got a faint positive again. But all of my tests have been negative since then. I’m breastfeeding and don’t have a cycle so I have no idea how many DPO I would be. All I have to go off of is that I just feel like I’m pregnant and my child is acting so clingy and ill. What’s the longest someone has gone with faint positives? When did they get darker and turn to a BFP?