OK hun, well first of all...dont beat yourself up many women drink and dont even know yet that they are pregnant! Usually it takes for them to miss a period to know they have a bun in the oven and then the drinking, smoking, ect. stops. And most of the time the baby turns out just fine. My best advice to you is: If you suspect that you might be pregnant, just treat your body as if you are until you know for sure. Stop drinking and eat healthy, take prenatals even. (That is if you plan to keep the child, I assume you are ???) And just wait. When we get preggers it happens about 2 weeks before the next expected period. This seems like a long time to wait for a result when you REALLY want to know! But its not that long. I am 13 weeks pg now, I just "knew" I was though...the going going going to the bathroom, sleepiness and increase in appetite and cravings (yes that early!) So I tested about 5 or 6 days before my period was expected and got a positive. I was very happy, we had been trying for a year! In your case this baby is a "suprise", just stay healthy, treat your body as if you are preggo and you will be in the clear.
BTW; If the "pull out" methosd has worked for you in the past, good but its not a safe and effective method (IMO) if you really dont necessarily want more children just yet. Semen can still enter the vagina during intercourse and it only take one little swimmer, it doesnt take the whole "bunch" of it to make a baby. Pulling out is helpful when used with other methods of BC. I would suggest (and this is totally up to you) getting an IUD (Intra uterine device) which is very small, inserted by a Dr into your uterus. It can stay in place for up to 5 years I believe (could be longer for certain types). The "Merena IUD" is great its safe, small and you can have it removed anytime you want a baby.
Basically...Just do some research of your own and find a good method of BC, that works for you and hubby. In my opinion (no judgment here) I wouldnt count on the pull-out method 100%, and especially if your lifestyle involves drinking for fun and things that aren't safe for a pregnancy add some more birth control methods that have proven to be reliable and are safe for you and hubby.