If everything turns out oke, you really should consider to get something to protect you. If he really want unprotected sex... Than go on the pill, get a helix or something else. nowadays there is So many choices
You can get it for free at women's health clinics. Possibly at planned parenthood as well. Try googling for a free clinic in your area
Do you have an adult who you can trust such as a aunt or friends mom? If so let her know the situation and see if she can get you a plan B. They are normally like $50 at the local pharmacy. Hope everything goes well
He hasn't been talking me into having unprotected sex. It was more of just a choice for both of us. He asked me how long till my next period but by the time I answered it was a little to late. I also don't have a way to get plan B
ps -- Your boyfriend knows nothing about human sexuality or the woman's cycle, and he is a selfish jerk if he has been talking you into unprotected sex.
17 days until your next period, and sperm can live in your system for at least 4 or 5 days -- that timing is not good if you are trying to avoid pregnancy. In fact, if you are trying to avoid pregnancy, you should not be having your boyfriend put his penis in your body without a condom, but that is another story. Get Plan B, take it today.
If it has been less than 72 hours you can go and get plan b. You probably should go get it. Your bf doesn't know what he's taking about cause unless you've been diligently tracking your periods and ovulation there's no way for you to know for sure when you ovulated. It's not a sure thing that you're safe. You should either get on some birth control or always use condoms or both if you don't want to get pregnant.