Second Trimester - Random One Time Sickness

[ROA88]

I’m 22 weeks going on 23 and was one of the fortunate ones who didn’t experience sickness during my first trimester. This morning (mid-morning) I had a sudden onset of nausea and then vomiting, the first in my pregnancy.

I’m not sure if it was something I ate not agreeing with me or the lack of sickness in my first trimester catching up with me, but has anyone experienced this before (no sickness first trimester and then a random onset 2nd)?

I had it when I lay on my back for a detailed scan (am still grateful to the lovely doctor who held my hair and fetched me water) - after that I felt sick if I lay or reclined on my back but was fine otherwise.