Could I be pregnant!!

I been having gas like crazy for last week in the half. My cycle was on the 24 it ended on 29 I ovulated on the 8. I been trying to convince for 2 months. I have heartburn, headache and boobs are a Lil sore. I took a test 2 day ago came back negative. I think the hcg was to low so I'm gonna take another on if my cycle don't come on.