Yes, what Alexandra said. The Morning After Pill is just something you take once, after risky sex, meaning a condom has broken or you've been raped. It's not birth control for daily use; basically, the MAP is a high dosage of birth control taken at once, but it doesn't protect you for a whole month. And it's not healthy to take that much on a regular basis.

No, you can't get STDs if you're only having sex with each other and you're both clean of intravenous drug use where needles are shared (or any drug use, because using drugs or excessive alcohol can impair your judgement and make you make stupid decisions that may put you at risk), and aren't otherwise sharing blood or other body fluids with others. For example, those who engage in vampirism and drink other people's blood do put themselves at risk, although I think most people into this lifestyle limit their partners and get tested periodically. But that's just an example of a potentially dangerous thing. If one of you got an STD through needle-sharing or such, then you could pass it on to the other, but it doesn't develop on its own.