Sleep Regression?

So my son turns 4 months on the 20th, but for the past week or so he has NOT been able to sleep at all. We usually start bed time at 7:30 and he will generally either pass out at 7:40-8pm. However, every two hours he wakes up. I know it is probably because of sleep association, but I have to feed him to sleep or else he really wont. And I just get so tired in the night that I just let him sleep with me at around 3am. Is this possibly him hitting the sleep regression now? I can't imagine what it is going to be like if it really isn't.