Morning Sickness but no BFP

A little bit of a back story.. Myself and my partner have been having unprotected sex for over 2 years, my period has always been late, sometimes 2 months late, making me worry that its maybe possible that I have pcos.

However, 2 days ago I woke up and had the sudden feeling I was going to be sick and right enough I did, I've had no symptoms of a sickness bug but have had lower back pain and pain up one of my legs, took a test today and it's come back negative, period hasn't been in probably 2 months now..

Just wondering if anybody has had morning sickness without a positive test result straight away!? Very confused and feel like my body is broken 😢