Thanks for writing to us.
Since you had your periods till 26th January, the chances of pregnancy
are not there. If you did not have any unprotected sex after the periods then pregnancy is ruled out. The symptoms that you are having can be due to a mild gastric upset which will gradually become alright in next few days.
I hope this information has been both informative and helpful for you. You can consult me again directly through my profile URL http://bit.ly/Dr-Rakhi-Tayal