What is my situation?

My period is due in 3 days, but I felt many cramps. An early pregnancy test was negative.

Someone recommend me to check my ovulation, so I just did. But during the test I noticed some blood, a little bit, as if I have an early period, which has never happened before.

Is it normal to have a positive ovulation test 3 days before you're supposed to have your period?

Can someone explain me what is going on?