Back up and punt. Don't do this at 18. Yes chances are very good at getting bad acne if you are succeptable to it. 8 weeks is long too, it's pretty harsh on your liver. Are you planning on using Clomid if gyno arises and then again post cycle? Gyno is probably a lot more likely than acne and Clomid is not your best bet for it, may help some but I sure wouldn't want to depend on it.