My cycle started one day late 5/7/17 I was using tampons but it was pinkish, sometimes nothing were on it but I filled the tampon one day after 4 hours and still wasn't red like it should of. I had unprotected sex on the 19th of April.Is it possible that I'm pregnant or am I just paranoid? I took a HPT 5/11/17. Negative results. When should I take another?