Idk what’s going on ..

I’m 18w/4d and I’m “cramping very bad tonight . This is my second pregnancy & with my first I was the “little girl who cried labor” every time I had a little cramp so I’m trying not to make a big deal about each & every little ache or pain I have with this one . I’m thinking it’s Braxton Hicks but with my first I didn’t have contractions this early & I don’t remember them being “painful” , these cramps literally feel like the worst period cramps I’ve ever had & they last longer than 2 minutes , also when I’m having them I feel a lot of pressure in my chest like something is sitting on me & I’m struggling to breath . I have an Apple Watch & have been checking my heart rate , it got up to 117 during one of the cramps . Is anyone else experiencing this ? I’m about to go to the hospital just to be safe , but I just wanted to see if anyone else has experienced this .