Nausea/vomiting question

Hi Ladies - I'm 17+5 and I was pretty nauseous throughout the first trimester but never actually threw up. The nausea has been better the last few weeks but still there before I eat in the morning and sometimes before dinner at night. Anyway, this morning it hit me hard and was the first time I actually threw up from it. I don't think I'm sick because I instantly felt better and have no other symptoms but I'm confused about why it's happening this far along. Just wondering if anyone else has had this experience? Thanks!