Hi everyone need help

So I'm on cycle day 4 well I was on af from the 3rd to the 6th of a very low grade flow but anyways now I feel nauseated 🤢 and got heartburn what does this mean I'm TTC I had bd on the 31and1st and the 3rd 4th and 5th I'm kinda scared idk why but is it possible that I got pregnant on what I thought was af and wasn't af I had spotting from the 31st and the 1st and then started going a Lil more in the 3rd to the 6th my lh levels or are low I have leftside pain really bad what is this