Yes, pregnancy is still a possibility, but based on what you have described, it seems less likely. A urine pregnancy test taken on 3 September would usually be reliable if conception happened around the expected time. However, sometimes the result can be a false negative if the test is done too early, if ovulation (the release of the mature egg) happens later than usual, or if the urine is too diluted. In your case, hypothyroidism and a raised TSH level may also play a role in delaying ovulation and disturbing the normal menstrual cycle (periods). Even after increasing your Thyronorm dose, it can take some time for hormone levels to stabilise and for periods to become regular again. Stress and hormonal imbalance can further contribute to a delayed cycle. If your period does not start within the next week, it is best to repeat the urine test with an early-morning urine sample or get a blood test for beta-hCG for a more accurate result. It is also important to follow up with your doctor to review thyroid control and other possible causes.