### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
hello i had unprotected sex on 8/5/10 and my period was due on 9/5/10 and i came on it as usual. however it was a bit lighter than usual and i was worried if i had become pregnant, although many say that if your period came as normal you are not pregnant, and it wasnt within the few days which im fertile. i am still at this stage really worried and stressed about it, my next period after that which began 10/6/10 and finished on 15/6/10 was to a bit light, but i wondered if that was because i have been stressing my self about it. i went to the clinic on 27/5/10 and my test came back negative, and the doctor said there was very little chance that i was pregnant and to wait to see if my next period came in which it did (luckily). i have been getting a few symptoms of pregnancy e.g. tiredness, stomach pain, constipation! although these symptoms can relate to stress and anxiety symptoms also! please please please help me, im worrying myself all too much till i know for certain :(

### output:

Hi, Thanks for your query.  I understand your concern.  - Sex one day before expected day of menses can not cause pregnancy provided the menstrual cycle is regular. Again in spite of all the pregnancy like symptoms, your pregnancy test was -ve... which is confirmatory.  - Following two cycles were also in time. But somewhat lesser bleeding. The associated symptoms of fatigue/ constipation/stomach pain are signs of psychological stress & actually your menstrual stress can cause hormonal disturbance & scanty period -Hormonal imbalance due to thyroid problems/ ovarian problems POD fibroid uterus . Also cause problem like you.  * Consultation of a gynecologist/ USG abdomen/ thyroid tests would find cause as well as satisfy you about absence of pregnancy.  Thanks.