Chemical pregnancy??

I’m 20 and had unprotected sex on my most fertile day not realizing it. About three weeks after I was throwing up and nauseous constantly and more emotional than I’ve ever been. My boobs were super swollen and sore and i always felt the need to pee. Time for my period comes around and I’m about 2 days late so I took a test one night and it showed up negative. Next day I started having insane cramps but no bleeding for about two more days when I started bleeding super heavily and I instantly felt normal again(not nauseous etc. ) I’ve read some stuff about chemical pregnancies and that sounds pretty similar but I’m just really unsure if that’s what it was..... if anyone has any insight on this it would be super helpful :)