Help..

Okay so I don’t even know where I should post this but this is what’s going on:

My SO and I have been TTC since December. This past month and a half we have been REALLY active and my last period was 4 days late and only lasted 3 days. I didn’t test I took it as my period and we decided that if my next period was late then I’d test. Okay so fast forward.. this month 18-24 I ovulated and we have been very ‘busy’ this month. Well today my right side almost directly under my belly button has been straining. I say straining because I don’t know another word for it. It kind of feels like a pulled muscle but it also feels like a cramp. I tried rubbing it like you would a pulled muscle but that made the pain worse. What is this? Could it be related to us TTC? Or is it something totally different? If so then what??