The last day of my period was on sat. Oct 1 I was suppose to get my period on the 20 bt I ddnt instead I was spotting for 2 days on oct.17 I took 2 pregnancy test and came out negative. Can I be pregnant?

It's possible... when did you last try a test? If it has been awhile, try another one, following the directions carefully. If you still do not have a period for this month and the test is negative, you can wait and see what happens when you would expect your period for December and test again at that time if necessary. Or you could see your doctor about having a test there.