Too soon?

So we've talked about having another baby but neither of us have made the decision yet. We use withdrawal but lately we're not as careful. Well I've been really tired and yesterday AM I felt sick then I was ok. That afternoon I got a headache and started feeling nauseous. The headache got better but last night I ended up getting real sick and throwing up all night. The kind of sick that usually only means one thing. AF is due tomorrow but I had one of those cheap 88 cent tests, not early detection kind but I took it this AM. I figured if there's enough hormones for me to be sick then there's enough to show up. Well it was negative but idk if it's just too early still. Guess I'll see what happens between now and tomorrow.