Hi I was just wonderin if it is possible for my friend to be pregnant.

She had sex around 3 weeks ago unprotected n her bf didnt pull out. She is sayin she was on the pill but 2 or 3 days later she started on her period. Her period has been mild but has lasted for just under 3 weeks now and she is still on. Normally she has normal regular periods but for some reason this 1 is different. She took a pregnancy test the other week and it came out negative. But she says a test isnt always acurate while on her period.

So I was just wonderin if she may or may not be pregnant. If not what is causin the period to last so long

please help any advise would do my friend good