Could I be pregnant?

So Saturday the 15th I had red kinda brown spotting with a little bit of cramping that happened for about 4 days my period was due to come the 19th I’ve taken a few test they were negative I am now “16dpo” and haven’t no period I am extremely nausea I’m tired my boobs hurt I feel like I’m pregnant but i don’t know is there a chance I’m pregnant and just hasn’t picked up yet “ I do wanna say my periods have been crazy” I did ovulate this month!