No, it's not entirely safe. Not just the Hep C or AIDS risk, although tattoo shops are required to sterilize their instruments....the much larger issue is that tattoo's are basically small incisions into the skin, and any time that happens you run the risk of general infection, as well as the dye itself entering the bloodstream, even in small amounts.
You're going to be a mom soon, get used to not getting everything you want.