Sooo I missed my period in May, I’m 16 days late and for the past few days I’ve been having brown/ pink discharge and when I wipe

I’ve also been having light cramps so when the discharge started happening I thought it was my period but I never got this before

Sometimes it’s lighter like in the picture but other times it’s darker brown and a little more heavy ,

I had a uti the week of my missed period and was taking antibiotics so idk if that’s why? I had sex like 4 times in May .

UPDATE some people in the comments informed me that it can’t be implantation bleeding but can y’all still comment what it could be