How To Reduce Abdominal Pain, Fever And Headache During Periods?

I have intercourse with my gf on 19th day after period.after two days i give her un wanted 72 .her period days are 26days.her period starts on 26ht day as usual.when perid starts she had a very pain in abdominal ,fever and head ache.plz tell me what medcines give her and is there any chnce of pregnancy and is her next period will normal i.e after 26th days. Can i have any test
do that shows accurate result.