Help !

My sister has a irregular period . she had unprotected sex about two weeks ago . she is just paranoid and wanted to some how see if she is pregnant . she took a pt last week (neg) should she take one this week ? She has been complaining she has had heartburn for the first time she has never had that before . also the top of her vagina (abdomen area) its hard . thanks any recommendations ? Also she has been bleeding for a week straight ( when she has a period its usually light and a few days)