Super heavy period??

Honestly I’ve never had a period like this, it’s kind of weird. My flow is SUPER heavy, I’ve had to change my pad 5 times already today and usually I only change it three times at most because I’ve never really ever been this heavy (and in the past when I’ve worn tampons, I’ve never had a full tampon, & for me to be bleeding this much it’s kinda trippin’ me out.).. my periods used to be super irregular but these past like three months they’ve been lining up, but this time it was 4 days late and I’ve been having unprotected sex, so I thought that maybe I was pregnant. My body was aching so bad so it was more believable, and now after every time I eat, I feel super nauseous like I’m going to throw up.. i have no idea what’s going on. Thoughts?