Hallow Dear, Even though the condom had slipped off, you have taken a due precaution to avoid pregnancy by taking Plan B post coital pill. I hope you have taken it within 72 hours of the incidence. It is a very effective method of avoiding pregnancy if taken within 72 hours. These pills have a couple of after effects: 1. After consuming pill, few days later, some spotting to scanty bleeding may take place. You had such bleeding. Not an issue of concern. 2. The following periods may get delayed by few days to a week. Though you have very light bleeding on the expected date, you may expect it to start like a normal menses within a few days. I think the possibility of pregnancy due to this act is very remote. However, if you want to confirm, you may perform pregnancy test on overnight morning first urine sample after 8 days. Alternatively you may opt for Beta hCG test anytime now onwards. I hope this provides you the solution to your query. Dr. Nishikant Shrotri