I usually orgasm before my boyfriend does, and we tend to keep going so he can get off. But lately I've been having very light bleeding spots. I don't know if it is because maybe he is causing an abrasion of some kind within me since I get sensitive after an orgasm. Is he damaging something?
It is certainly possible that sometime during sex you are getting some little abrasions that are causing you to spot afterward. Since you are not bleeding heavily, the abrasions are probably not serious, but just enough to cause some irritation. If you are not having this issue during other activities, then the most likely culprit is a lack of lubrication. Because of the way our anatomy works, women pretty much produce lubrication during one part of arousal and then don't really produce much more after that (this is not true for everybody, but it is for some). With all of the friction associated with sex, and especially with condoms that lubrication that is naturally produced (and even added artificial lube) can get dried out before we want to be done. An easy fix for this is to add some extra lube at various times during sex.
You don't mention whether you are having discomfort during sex associated with this or not. It is common to become extra-sensitive after orgasm. If you are having some discomfort or pain when you continue intercourse, then the best thing is probably to take a break after you orgasm from that activity for a while. There are plenty of other activities that you can engage in that will be pleasurable for your partner and avoid any pain for you. You can either do those activities until your partner orgasms or until you are no longer quite so sensitive (AND you wish to engage in intercourse again).
If you haven't had your annual sexual health exam, now would be a good time to do that as well. Some STI's can cause sex to be uncomfortable. This may not be associated with what you are experiencing, but it's always better safe than sorry (and you will also have the opportunity to speak with your health care provider about this and maybe get some other suggestions).
You may find the following pages helpful:
From OW! to WOW! Demystifying Painful Intercourse
Sexual Response & Orgasm: A Users Guide
Sexual Health 101: Hers
Condom Basics: A User's Manual