Weird contractions .

Ka

I can’t tell if they are real contractions or strong Braxton Hicks..... but when I get them, before the tightening or cramping even starts, my head pounds really bad, my chest gets tight and I get crazy hot! I never had this with my other two pregnancies so this feels weird. It goes away when they stop but it makes breathing through them so much harder to do. Has anyone else ever had this? I’m 35+4.