Hello, With reference to your query regarding Plan-B that you should take 1 white pill within 72 hours after unprotected sex and 1 whiter pill 12 hours later. Each dose contains 0.75 mg of levonorgestrel. The 2 pills are identical, it does not matter which pill you take first. Both doses can be taken at the same time up to 120 hours after unprotected sex. The pills are more effective the sooner they are taken, so take 2 Plan-b pills at the same time as soon as possible after unprotected intercourse. It is a way to prevent pregnancy after unprotected sex. It contains only the progestin Levonorgestrel. It is not the same as RU-486-the abortion pill. You should not take Plan-B if you are already pregnant since it will not work. It will not cause birth defects. Both can be taken at the same time with no decrease in effectiveness or increase in side effects. It should be taken within 5 days (120 hours) of unprotected sex and can reduce the risk of pregnancy up to 89%. It is highly effective but not a substitute for a regular method of contraception, because it is not as effective as regular contraceptive methods. It is more effective than emergency contraceptive pills (ECP) containing both estrogen and progestin. It is safe for almost all women. It does not protect against sexually transmitted infections including HIV. The side effects of Plan-B include nausea, abdominal pain, fatigue, headache, menstrual changes, dizziness, breast tenderness, vomiting and diarrhea. It causes less nausea and vomiting than ECP's. You are already started bleeding and after 3 weeks, your periods have started as normal. What you are experiencing is nothing but it's side effects. If you are still doubtful, either you can contact your G.P. or health worker or a gynecologist. Thank you.