I Was Put Under To Get My Wisdom Teeth Cut Out And Now My Period Is Almost 2 Weeks Late, Is That Normal?

My period was supposed to start on the 6th but I have been under a lot of stress and it was a week late the month before as well so before I was a week late this month I was put under to have my wisdom teeth cut out and I spotted the day after surgery but now no signs of starting and it is the 18th. I was just wondering if it is normal? I took a pregnancy test and it was negative but getting worried.