So emotional

Brittany • Chloe Elizabeth 7-30-13. Sophia Grace 10-15-15. Baby #3 09-20-16
Man, I've been an emotional wreck these last few weeks. Thankfully my boyfriend as been so understanding and comforting. One minute we can be laughing, then I pick an argument over something stupid, then start crying because I feel so bad and then everything's fine again. I just broke down because I'm worried about miscarrying and every little pain or new feeling makes me so nervous and like I'm miscarrying again, until my bf reassures me that everything is going to be okay with our little bean. 12 weeks 2 days and I'm more worried than I should be. How do I ease these worries and stop stressing so much?! I had an ultrasound at 7 weeks 6 days and our baby had a heartbeat of 165. I have another ultrasound on Friday, then I'll be 12 weeks 5 days, but I'm becoming anxious waiting until then.