third trimester morning sickness?

JSS1002

I've heard of this happening -- anybody here to share an experience?  I will be 28 weeks on Thursday and the past few days have woken up with nausea, similar to when I was in the first tri. 

I didn't expect this to come on so quickly into the third tri. 
I could also be having a sour tummy due to an anti-biotic that I'm on.