Questions on the shot

Having children is really important to me, but in good time. I'm 21 and my boyfriend and I are sexually active, but aren't ready for any children yet. I'm on the pill right now, but considering going to either the shot or the implanted rod. My only worry is, these types of birth control cease ovulation. This means that they are really effective, but do I run any risks with my fertility after coming off of the birth control?