Cramping or something else?

[omnipadme]

Last night after doing the "do," I had the worst pelvic pain i've ever had. I've been feeling crampy and nauseas for the entire month, so I figured it was the same thing. After a few minutes, i was hurting so bad that I couldn't move. This is pretty much how I spent the entire night- laying on my back immobile. I got up once to use the bathroom and couldn't even sit down. Eventually, I just took some pain killers and it went away, but should I be worried? I have not had a confirmed bfp, testing on sunday. I was worried I might be experiencing a mc or etopic. This is our first try at pregnancy, so I have no idea what's normal and what's not.