Since you are due for your menses on 3rd october, it is too early to visualize a pregnancy
on ultrasound even on a transvaginal ultrasound
. Pregnancy can be seen earliest at 5weeks on TVS.
So for now you should get a urine test for pregnancy incase you havent got your periods yet or better get a blood test
for Beta hcG to be absolutely sure.
The findings you have mentioned as on your ultrasound are normal findings. The unilocular cyst
you have mentioned in the ovaries is too small to be managed and is common in reproductive age. They usually disappear in next cycles.
The only possibility of the cyst being a cause of worry is when your beta hcG is positive and no pregnancy is visualized in uterus. It can be an ectopic pregnancy (pregnancy elsewhere than in uterus) . Ectopic pregnancy can be confirmed by repeat ultrasound or repeat blood test for which you have to consult a gynecologist for proper sequence of tests.
For now you just get a blood test for beta hcG to rule out pregnancy as a cause of your symptoms of sleepiness, lightheadedness
, fatigue , back pain
, fullness of lower abdomen, frequent urination
Incase its negative, you can relax.
These symptoms can occur in thyroid disorders so for that you get a Serum TSH done and consult a physician.