We people here are a bit rude about the possiblity of killing a embryo. Either plan your sex right or dont have sex. If there is a chance of getting an unplanned pregnancy, you should use condom, without fail.
Let me correct on few things, her period is supposed to be on 15th of June, means last one was on 17th May. Having sex on 22nd May, there is hardly any chance of getting pregnant. Even if she is, better to own it as your mistake. We dont recommand any illegal act like abortion. Abortion should only be chosen when there is a health reason.
Let me correct you on cum outside. On the first fuck, you can cum outside. Then for the next shot, you should wait for at least 2 hours, else sperm remains active on the line. With the precum this sperm can get her pregnant. If you come outside on second and third fuck, sperm is present there.
So you are adult, she is adult. if you get her pregnant, marry her. I can sense the depth of your love, first meet and three fucks, she must be either loving you so much or she is a professional blackmailer. Whatever the case is, we dont want to hear the term abortion.
You should have used condom, next time dont repeat the mistake, specially you never know if she was carrying any STD.