Why can I function normal no matter how drunk I am?

So to start this off, I’ve never been much of a drinker, nor have I ever consistently drank for a long period in my life. I’ve always been able to down as many shots as I want and still act normal. I’m not saying sober by any means, I understand my reaction times are slower, I don’t drive, etc. I just act like me? Like I’ll clean or cook or do normal activities. Even in social gatherings people have gotten so confused by my ability to “keep up” and still appear normal. I drink maybe once every 1-2 months (I’m 6 months pregnant so I haven’t in a fat minute but I’m chilling), sometimes it’s a lot other times it’s a beer. I’ve always been able to remember everything, I’ve never done anything out of character. I honestly thought people were faking it and using being drunk as an excuse since I’ve never had this out of control experience. Alcoholism runs in my family and they were typically violent, I’ve made it a point in the past to test how many drinks I could take before I got violent and I never did. Being drunk if anything makes me a bit freer/happier but nothing has ever really changed. I’ve always been quiet, I don’t become a social butterfly. Is this a sign of alcoholism if I don’t ever have the urge to continually drink or drink alot? I have autism so idk if that affects anything.