Help pregnant??

I’m 12 days late with my period and have had an on track period for the last 7 months, the test came up negative and I don’t know what to do. I feel sick and have had cramps but no period. I have also had really bad heart burn. When should I take another test? The last time I took one was 4 days ago. I have sex almost daily and we haven’t been preventing pregnancy but haven’t been trying for a baby either. I’m just unclear about what step I should take next.

Update: I thought I started my period but only bled twice both times when going to the bathroom and have thrown up today. Any ideas ???