Your friends are wrong. If you rubbed your vagina against his penis you could be pregnant. The chances go up if he's masturbated recently because there will still be much more sperm in his penis.
It's true that being very active can delay your period. You can even skip periods if you're very active, not eating enough, or you've been sick.
Since you're late you can take a test and it should be accurate. They can be bought at any Dollar store and at Walmart for 88 cents. I hear these tests are just as accurate as the more expensive ones.
I highly recommend you don't do this with your boyfriend again unless he's wearing a condom, rub against his penis. He should not touch his penis and then touch your vagina without first washing his hands with soap and water. Sperm can't live long outside of the body but if he touches his self and then touches you right away the sperm can still be alive and you could get pregnant.
Has your boyfriend been tested? I'm asking because you can get oral herpes if he he has it by giving him oral sex. You can also get an STD by rubbing up against his penis if he has genital herpes.
I'm always here to listen and give you any advice I can. Take a pregnancy test and if it comes back negative then you know your period is late because you've been so active. If there's anything you don't know about sex you can always come here and we'll do our best to give you the answers. Or, you can google questions.