What could this be? Have you experienced it before??

Ms
I am 22 weeks pregnant. I suddenly have these small red raised bumps all over my sides. They go onto my back and stomach a bit, and slightly down my thighs...but it's predominantly on my sides.
They don't really itch. If I touch them then they feel slightly itchy...but if I leave them alone I can't feel them at all.
I haven't changed anything so I don't think it could be allergies...
Any ideas? Have you ladies had this before??