Looking at your posting history, I see that you've been to the HIV Prevention Forum a couple of times as well as the HIV Anxiety Forum. I see that you understand what you need to do regarding testing.
What I am wondering is if you were raped.
Were any friends with you when this happened?
One question I have is why you didn't call the police?
It's pretty normal that while waiting to be tested, you would be feeling some intense anxiety, even panic. There is only one thing I can think of for you to do, and I would strongly suggest you do it soon, is to get into therapy and begin dealing with everything that is crashing down on your head. Not being able to remember is going to make it more difficult, but you need some support and guidance immediately.
If you were having an affair and it was this man who spiked your drink, that is date rape. If it was a total stranger, that is felony rape, but either way, the police should be notified. I know this will get your husband involved, but if you were raped, you need his support far more than ours.
If you can't share this with your husband, please make sure that you know how to protect him and your son by educating yourself about the ways HIV is spread. You can be tested for all other STDs now and I hope you've done that.
A test for STDs, therapy and calling your local rape hotline are the best I have to offer. Besides my heartfelt hope that your test is negative.
are you scared to be pregnant? where were you that you got drugged?
Wait for the result. Cross the bridges when you come to them. If you feel that your anxiety's taking control, see your Doc. He can help. Best wishes.