Last month I got my 1st period since I gave birth (son was 14m) before pregnancy I was having regular periods for almost 2.5 years. I would get them every month on the 21 or 23rd right around there....My last period was on the 16th of march, on the 8th of April I had unprotected sex. On the 11th- 13 I had dark brown spotting when i wiped enough to notice. I was expecting my period no later then today and It still hasn't come....I've had a sinus infection for a week (still have), horrible acne showing up, lower back pain, headaches, and was puking for two days earlier in the week, and still no period. I'm still nursing my son but not nearly as frequently. I took a pregnancy test on the 16th and it was negative. Should I be concerned? or just wait it out? Could a sinus infection effect my period? What is the likely hood of conception? Thank you.