My husband and I have been trying to get pregnant for 7 months. I've been having regular periods with no bleeding in between. According to my calendar, my ovulation was 4 days ago. Today I'm having light bleeding and cramps I'm supposed to get my period in days. Is it possible this is implantation bleeding? I'm so worried that this is a miscarriage. Should I call the doctor? Any comments would be helpful, I'm scared and worried. This process is so hard and I'm feeling very discouraged.