The pill is only good for up to 72 hours after sex. The closer to the start of the 72 hours, the better. Since you were still in the 72 hour window, it's possible that the pill will work. However, sperm can live 3-5 days. So to be sure, you would have wanted to do another dose of the MAP. At this point all you can do is wait to see if you do get your period. Do keep in mind though that that MAP is not a form of birth control, as it won't work as well as regular contraceptives
Basically it's a 50/50.. I see now where you said you took it that night for the first dose, so the 2nd dose was Saturday morning.
Then sex Sunday, which I assume is at night as well. As stated earlier, sperm can live 3-5 days, so the pill wouldn't work if you ovulated say Tuesday. As pregnancy could occur then. (if it's time for your cycle)
The medication only stays in your system for a couple of days. So if you took the 2nd dose on Saturday morning then figure 24 hours and it's gone. So Sunday night you would have needed another dose.
If you are generally regular each month, and are on a 28 day cycle and give me the first date of your last period, I can check to see when your possible ovulation date would have been.
Hope this helps.
The only one that would be pretty good is First Response. It states it can detect pregnancy up to 5 days before. However, is it 100%, for some yes. But since you know when you had unprotected sex, it's best to wait at least 14 days after if not 19 days. As every woman is different when it comes to how hCG levels rise. So if you do not have any period by day 17 from Saturday, then do take a test. Keep in mind though a blood test with your doctor is most reliable.