My gf took plan b and its been already2 weeks and she hasnt had her period when should my gf take the pregnancy test ?

Now: If she has missed her period take the upt; the Plan B may have offset the period a bit because it alters the uterine lining. Check my statistics but i think Plan B reduces the pregnancy risk by 75-80% depending on when it was taken. You want it prior to 72 hours after intercourse. Baseline rate of pregnancy is about 15% per month or so, odds fairly low of pregnancy but if peg a upt should be +.