Thanks for your query.
I will try my best to provide you with best possible professional recommendations to your questions.
As her period is not irregular it will be difficult to pin point the safe period. Even drop of semen and sometime even Pre-ejaculate
will be enough to get pregnant.
Due to the ruptured hymen
bleeding will be slight and it will not be continues as in menstruation
. Slight spotting can occur in pregnancy
I advice her to go for urine pregnancy test, a kit is available in almost all the drug stores and instruction how to perform the test is mentioned in that kit. I advice you to perform the test using early morning urine sample, test is nearly 99% accurate. It will aid in knowing whether she is pregnant or not.
Yet again, I do hope that you have found something helpful and I will be glad to answer any further query.