Has anyone been nauseous in recent months? I didn't have nausea throug…

Has anyone been nauseous in recent months? I didn't have nausea throughout my pregnancy, but here it is already the second time after four days that I feel sick. The first time I woke up in the middle of the night, and now I sit and feel very sick, really bad. (I haven't eaten any outside food, I eat as I always did, and nothing new has been eaten these days). What could this be? I read on the internet that it's kind of a sign of labor, but I'm still too early, only 34 weeks. Has anyone had this?