I was suppose to have my cycle 4 days ago. Usually I’m only on my cycle for 3/4 days and it’s usually heavy bleeding and I have been able to track it every month. I have never had an irregular period before. This past cycle there was barely blood more of a spotting and light pinkish discharge and minor cramping but it is short, not long like I usually have cramps. Are these possibly signs of implantion and if so when should I take a pregnancy test?

I have been taking a few they look negative but the second line is barely there it’s super faded. I heard I have to have enough HCG in my body to have a BFP. When should I take another test?