Scared???

So I usually have periods every 32-38 days I'm going on cycle day 50 and still nothing, my boobs hurt, I have nausea at times, I'm testing tomorrow morning. But I'm already shaking because my son is now 9 1/2 months old born on November 4th 2016 at 27 weeks gestation. My SO and I have not been trying and I have not taken clomid like I had to with my son, I just am terrified that if I am I'm going to have another preemie and I don't think I can do that again!!!!!!!