Talk to Gynecologist on Pelvic Pain

This is the first time in my life that I having a severe pelvic pain during my periods with a very light flow, unable to walk properly, sit and lie.. My normal period duration is 5 days, but this time I had my periods only two days after that very abnormal flow, I can say like very light spotting after an hours.. I did my pragnancy test at home with pragnancy strips and it’s positive. So what can be the reason for that?