Unexplainable nausea is fun.. not

Woke up at 4am feeling really nauseous. Made a quick trip to the restroom thinking it was going finally happen. It then subsided. Now I have heartburn so I guess it could be from that. I really don't think I'm pregnant, but at the same time I have no idea when or if I ovulated recently. I haven't had my cycle come back since baby #2, yet. Only thing I had was some brown spotting on the 18th. So, while I don't think I am this nausea has me wondering! Anyways, thought I needed a rant since I'm now awake at 4am.