Almost 1 week late with period

I’m not sure what’s going on so I’m giving this a try . I got my first period already I was 6.5 weeks PP but me and my other half we have unprotected sex every time and this other day I have a pink light bleeding that only happen just that time after that it didn’t come back which I thought it was my period because it was suppose to come the week after, but I guess it wasn’t . I took pregnancy test 1 day before my period was suppose to come it was negative.Then I took another one 6 day late on my period it still came out negative. So now I’m just waiting till I hit one week late on my period to take another. I don’t know what to do honestly I’m new to this my periods are never this late but since I know that I’m breastfeeding it would be that way. PLEASE ANYONE HELP