I took plan b last month and when I was supposed to ovulate I started my period for about 4 1/2 days. I was supposed to start the 14th or 15th but I haven’t. I’ve taken two first response pregnancy tests on the 16th and 17th because if I were to be pregnant I would be about 4-5 weeks. Both of them quickly showed up negative and as a very clear one line. However I’m not really having any signs of a period, is this normal?