it should be fine if you still have other pregnancy symptoms like tender/sore breast. I thought my morning sickness was getting better at end of week 11 coming to week 12 but after a good day of no vomiting & minimal nausea, the following 2 to 3 days were bad. like my morning sickness came back w a vengeance and today, I feel better again with slight nausea (like start of pregnancy) but no vomiting and I sincerely hope tomorrow would be the same for me. I think the red flag for miscarriage is usually red bloody discharge and menses like cramps... as long as these don't happen, you should be fine. don't stress yourself!