Cramps?

Ya
We've been ttc for about 3 weeks almost. I already passed my fertile week . This last week. And I started feeling some slight cramping and I feel like my ovarys have a little bit of pain. It feels a little bad to actually sleep on my stomach? Could it just be me? Or something actually changing.? I took a test last night and it was negative. Period around the 22 of this month .  help!