Hi I'm A 22 Year Old Girl My Periods Have

Hi I'm a 22 year old girl my periods have always been on time pretty much the last one I calculated was in August and it came exactly on the 17th, in September I remember it being a few days late but came around the 18th-19th. It is October 24th and I've been waiting to get my period for almost 8 days now. I just took a home pregnancy test and both were negative is there a chance I might still be pregnant? I really don't have any symptoms my boobs feel fine not too much cramping, a little nausea in the morning today but I could very well be freaking my self out. My boyfriend and I only had sex one time after my period in September, he didn't bust in me at all unfortunately I wasn't on any birth control at the moment. I was recently on depo for 3 years but have been off it for a good year now. Please give me advice I'm not ready to have a baby right now..I know the tests came back negative but where's my period?? Thanks for you time, Emma