Vomiting and Nausea

Hi, nearly 35 weeks and last night was expecting a large amount of what I believe were Braxton Hicks and loads of pelvic pressure to wake up this morning with nausea and after drinking something I vomit.. never experienced morning sickness in the first trimester... any idea why I’ve now got nausea and vomiting not that intense to be a stomach bug only threw up twice it’s just very sudden