Pregnant?

I know I should just go get a test but was wondering what you guys think.
I'm going to sound like a horrible person but here it goes:
So my ex boyfriend and I for 3 years broke up in September, he completely crushed my heart and even asked me about another girl (if I thought she was hot and if he should fuck her). He ended up sleeping with her. After I found out I started cutting myself again, drinking & crying myself to sleep for almost 2 weeks cause I couldn't believe that after 3 years of being with this man he could just replace me like that. Because of all the stress I started sleeping around. I slept with 2 guys and didn't use protection with either. I'm horrible I know. Well I just had a child almost a year ago now and I know it's easier to get pregnant once you already had a child. I missed my period in October, still hasn't came. I'm not really feeling any symptoms. Although I've been extremely tired all day and night no matter how much seep I get. I don't know if it's from all the lack of sleep building up or what but it's been going on for about a week now. Also this morning I felt sick, I didn't throw up or anything just felt a little tummy sick.
Go ahead and roast me.