Late period and I am not pregnant

Hello ladies pls I need y’all advice and I know you always come through that’s why I am here.. I had sex with my bf four days before my period and it’s 5 days past my period now I haven’t started, it’s meant to be 25-30th at first I thought I was pregnant and yesterday he told me to take a pregnancy test, to my greatest surprise I wasn’t pregnant and my period is not coming up, pls what can I do? Mind you I braid hair and I I stand a lot my legs even get swollen sometimes so I don’t know but to me I am beginning to think it’s stress that’s what my bf says too, but yesterday I had a little tiny drop of blood and that was it , I even drank a whole pineapple that I blended for the period to come on time that was on 28th but still nothing till now ... pls what can I do? And am I okay? I have missed my period for two months before and I wasn’t pregnant although then I did not have sex that’s the difference between then and now that’s why I am scared..