Fifth day of placebo, no period!

So I just switched to junel fe, a higher dosage of hormones for my pill, I was on ortho tri cyclen for 4 months prior. I'm on my fifth day of placebo pills and no period! I don't have any symptoms of pms.. I am sexually active but my bf and I use condoms everytime and I check them everytime after to make sure they didn't break, which we haven't had any problems. Should I be worried?