My hubby and I have been trying for #2. Few weeks ago my nipples were really sore. (it was the first symptom with my first pregnancy) 2 days ago I got what I believe is my period. All day yesterday and today It's been so bad that I am leaking though a OB supper plus tampon in 45-75min. I'm wondering if it could be a early miscarriage?

It's possible, but there's no way for us to know. If it is an early miscarriage then you most likely won't need medical attention, your system will flush itself out, but if you're worried then see your doctor. But, it does sound more like a period to me. Sore nipples is also a symptom of PMS.