14 wks pregnant and just found out husband's cheating

I'm not looking for advice or sympathy. Just trying to test out the news to perfect strangers before I have to deal with the family and all their questions. I won't go into crazy detail because I know no one actually cares.
My husband just called me and told me there's someone else. He's been seeing one of his coworkers and they started sleeping together a few weeks ago. He's a restaurant manager, so it's not unusual for him to come home at 2-3 in the morning when I'm already knocked out. So, this is a huge surprise to me. 
I'm not crying. In fact, I'm completely numb. I'm sitting here just trying to absorb it all. Trying to accept the fact that I will be raising this child on my own, along with our five year old with autism. 
I'm prepared for the avalanche of questions like, "how were you too stupid not to tell?" Not only from you, but from my family. No one will believe me when I say I really believed we were happy and doing well (I guess I see now why he was always in a good mood.) All I can do, I guess, is just say, "yeah, you're right. I'm stupid!" 
So, here it is in writing, the end of my marriage and the beginning of my life as a single mother. Now, its time to pack some essentials and figure out what I'm going to tell my son. If you read this far, I appreciate it. I know I won't be able to get a word in edgewise later on to my family, so its nice to know someone heard me out, even if its just to criticize.