How soon can you take a blood test?

My boyfriend and I were going through a pretty rough place and I didn't think I'd be in need of my BC anymore and I felt like I was always so emotional since I started them so I decided to stop. The day after we slept together and then again a week later and have been consistently ever since. I'm nervous that I'm pregnant. I've been pregnant before and last time I said I'd always know if I was again but I can't tell. I'm having weird little cramps. I'm extremely exhausted like not normal tired. But I haven't had sore breast and that was my biggest symptom when I was pregnant. I hate waiting I want to know already. And I haven't drank because I think I am but with the holidays coming up I just want to know already!