My periods are due (almost 20 days), my stomach is getting bloated and in fact it is growing. I am having constipation and acute gas troubles, stomach doesnot feel fine, I have no appetite , no food carvings, no nausea but I do feel puckish but have never actually vomited.get easily tired and having bad mood swings can I be pregnant??

Yes, you could be pregnant. But you could also have a variety of other things wrong that may need attention. I would start by taking an over-the-counter pregnancy test first. If that's negative, I would make an appointment with a doctor to get checked out. If you are pregnant, I would also make an appointment to make sure you are indeed pregnant and go from there.

Pregnancy test can be taken with the first urine of the morning after missing your period by two weeks. It's not clear from your question whether you missed your period by 20 days or you are expecting it soon. Can you please clarify?