Please help ftm

So I threw up late last night from having heartburn even after I took my heartburn meds and then this morning I woke up and threw up again and I've thrown up 2 times since this morning and before I throw up I feel really bad for a while and my stomach is super hard up top and it hurts then I throw up and its better I'm 25 weeks pregnant and it's not normal for me to do this. Is this braxton hicks contractions making me puke where my stomach gets so hard and tight???