I'm very strict on taking my pill the same time everyday. I have never missed or been late in a pill this month. I also have been very sexually active this month but use condoms. Never broke. We did have sex twice without one but he never finished in me. I have taken 2 placebo pills already and today I'll take my 3rd one. My period hasn't come yet. I took a test this morning and it says not pregnant. Why is my period not coming? Should I worry?