Try to relax a little bit.
You are 18yrs old and your 16yr old GF takes I-PILL within 72hrs of unprotected intercourse
I think that's very good.
It is an oral emergency contraceptive pill
,which can be used to prevent undesired pregnancy
, in case of unprotected intercourse or failure of contraceptive measures.
**Emergency contraceptive pill is a safe and effective method of preventing unwanted pregnancy. The side effects that some women may have after using the tablet includes:
1) Irregular menstrual bleeding
2) Nausea, weight gain and breast tenderness
, mood changes
It can cause the next period too early or later than normal.
So dont worry about the thing and wait for next period.It is just withdrawl bleeding. Take care of your GF.
All the best.