If he said he came 3 times he would have def known it. If he did cum 3 times with no interuption, wow....good for him. I just think it's a tad unlikely that he did cum 3 times without a little resting in between. It takes a guy a little time to gear up for the next ejaculation. So if he said he came and did not pull out after but kept going and said he did twice more, i would say he ejaculated inside of you. I also find it funny that he did not express the fact that he was about to cum, he must be a quiet cummer, which is possible. When a guy cum's the head of his penis becomes very sensitive for a few minutes, that is why they usually rest for a minute, either inside of his partner or out. After the sensitivity subsides, he can usually begin again with out an issue.
You have 72 hours to get your hands on Plan B which you are of age to buy it. I would to be on the safe side. You mention that you have both safe and unsafe sex and have never gotten pregnant. I think you need to rethink that for a minute. Rolling on a condom takes a couple seconds, raising a baby takes 18 to 21 years. Hmmm...you do the math!