Masturbation during pregnancy

While I don't have much sex drive, I feel urges to masturbate when pregnant just like my last pregnancy. I've always masturbated by lying on my stomach and clit stimulation. I'm 19 weeks and have a tummy but not uncomfortable to do it this way still. Am I still early enough in pg where this is ok? My stomach isn't completely flat on the bed because my hips are propped up. How do you masturbate with clit stimulation when pg?