On my period again after 2 weeks

Ladiesss I need your help!! I'm on my period AGAIN after 2 weeks of my normal period . I started spotting on the 14th which was my ovulation day & im stillspotting . My initial period wasn't normal . It was light the entire 8 days and I'm usually not on it for that long . I didn't think anything of it .

I'm freaking out because I took a test and it was negative & im on this emotional roller coaster. Could be a medical problem I'm thinking. We are trying to concieve but haven't been successful for the past 3 1/2 years .

HELPPPPP