I got an iud removed late last month and started my birth control pill (sprintec) this month. I was taking it well and then I went on antibiotics (I asked the pharmacist if these ones were known to stop birth control and he said no worries) so we accidentally had unprotected sex twice back to back and I went and got plan b immediately (even though my period was supposed to come in a few days). So now I’m messed up. I took the plan and wiped and saw one saw drop of blood. Then when I was supposed to get my period it never came. I tested and it was negative. Should I retest?