Hallow Dear, Delayed periods and dizziness can be either due to pregnancy or due to hypothyroidism. Sleepiness is a classic symptom of hypothyroidism. However, nausea and vomiting do not characterise hypothyroidism. Please get your T3, T4 and TSH examined. Hypothyroidism should be well controlled during pregnancy lest the risk of adverse outcomes of pregnancy. Missing a period is, in fact is the first cardinal symptom of early pregnancy. All other symptoms like nausea & vomiting, frequency of urination and breast symptoms appear about a week or more after the missed period. However, nausea and vomiting may appear earlier too. All these symptoms are suggestive of pregnancy and need diagnostic confirmation. At this stage, some pregnancy test will detect the pregnancy if it is present. Urine pregnancy tests are best reliable only after a week of missed period; earlier they may report false negative. So you may perform this test on the overnight early morning first urine sample one week after the missed period. Alternatively, you may opt now for Beta hCG test which is highly sensitive and can reliably detect the pregnancy even few days before missing a period. I hope this should help you at this stage. Dr. Nishikant Shrotri