A flood of progestin frequently destabilizes the endocrine system for several weeks. Plan B side effects and bleeding patterns routinely generate false alarms among users monitoring themselves for early signs of pregnancy. Nausea remains the most common acute symptom, affecting roughly 15% to 20% of patients, often accompanied by abdominal cramping, headache, and fatigue.
If you vomit within two hours of taking levonorgestrel, absorption is compromised. In that event, contact a pharmacist immediately; you will likely need to take a replacement dose. Do not assume the pill dissolved if you throw up within that narrow gastrointestinal absorption window.
Vaginal spotting often appears three to seven days after taking the pill, caused by an abrupt drop in circulating progestin as the synthetic hormone clears your bloodstream. This withdrawal bleed is not a regular period, nor does it guarantee you are not pregnant. The true menstrual cycle typically shifts: your next full period may arrive two to seven days earlier or later than usual. If menstrual flow is delayed by more than one week past its expected date, begin screening for pregnancy.
Pregnancy test timing requires biological patience. Taking a urine screening test 48 hours after unprotected intercourse yields zero actionable data, as human chorionic gonadotropin (hCG) is not produced until several days after implantation. Reliable home urine tests require waiting at least 14 days after intercourse, with definitive confirmation occurring at 21 days. Testing earlier frequently produces false negatives that obscure an establishing gestation.
