A question about sperm and sperm count?

Okay so im 15 years old and im a girl, i dont know much about this, but im asking cause of my boyfriend, hes 16 , i dont know much about how this is, i just know that well we had (we where both virgin, our first time), our condom broke, i was scared of a chance of getting preagnant because of this. but i already took the plan b pill, so i feel a little less worried now. but he told me he might be sterile he thinks he might be, he probBLY told me that cause so i wont worry he'll get me preagnant ,i know, but nope. hes smoked a bunch of weed b4 ND done some drugs, he stopped, but i think thats the reason why he thinks he might be sterile, and well im not sure why else he told me he thinks this, (i was probably spacing out when he told me about the why he thinks he might be sterile, cause i space out a lot it sucks, but this is serious so..help_well now he told me .. okay, i heard something about pre-***?, and whats the difference between the sperm and semen,? he told the doctor, some doctor that all he gets is clear liquid, but then he said that the doctor was like 'so?', then he asked well doesnt sperm have to be white?, then that doctor said that no not exactly,that he has to get his sperm checked through a microscope and that it has to be fresh?the doctor didnt mention anything about him going to a sperm bank, but should he? i seriously dont really understand this, but im trying to help him here, i mean i dont know what should he do?, get him self checked, where? explain this a little?now he says that what the doctor mean is that well u cant tell by appearance, that u gotta find out through a microscope, ? where at the sperm bank?, yeah again i dont know much, but what does he need to do?naive about this and many things, im sleepy right now, but im worried about this, so thats why im trying to ask..i wasnt sure if i should ask here but well yeah