Implantation bleeding so confused need some advice ❗️

So I did not receive my period for last month so I assumed I was pregnant but after taking test after test and getting negative after negative I knew I wasn’t pregnant but this month about 3 weeks ago I had sex and two weeks later very light bleeding that only lasted a few hours for about 4 days it was pink in color so I just assumed implantation took a test 3 days after that and another BFN again idk if I should test again In a week or so or make an appointment because about 8 months before now I had a molar pregnancy and I just want to be safe but I just feel like I am pregnant one day and the next I’m not so I don’t know 🤷🏼‍♀️ I just have no hope after all the bpn’s