rhythm method

So, back in November I decided to stop taking BC-I've been on it since I was 16, and the husband and I thought we'd start trying in June/July (I'm a teacher so if i can time it out right, I can be home with the baby for 6 mo!). We decided to try only having sex when we knew I wasn't ovulating (I've been taking tests and tracking) and leave it up to fate. Last month, we had sex while I was ovulating but glow said I was only about 12% fertile. Shortly after, I got really sick and we haven't had sex since. 
Fast forward to today- no longer sick, no other pregnancy symptoms, but was supposed to start my period 2 days ago. 
What do you think? Should I buy a test? Should I continue waiting it out??