My period is about 6 days late. I am having some pregnancy symptoms , but the test has been negative. I have been pregnant before, and never got a positive pregnancy test , and that pregnancy ended in miscarriage at 8 weeks. Shortly after, I was diagnosed with hypothyroidism , which is now regulated. I just started a new batch of my prescription, so I have been convicing myself that the new medicine had enough extra hormone to throw off my cycle. Should I see a doctor for a blood test before a miscarriage again?