I had my last period, the first week of July, and I didn’t get a positive until mid September, eventhough, I had all the symptoms. It turned out that I got pregnant in August, but I had missed that months period. If you go to your doctor and ask for a bloodtest it would be best. Simply because they can track the HCG level as low as 5. If you have low iron, you could also miss your period, and be extremely tired. your best bet is to go to the doctor and have bloodwork done, on everything. 🙂