Confused? Should I give it more time ?

So I haven’t had sex since the beginning of the month and I used the plan B pill the next day.

Since then I haven’t had a period and I’m 10 days late.

I’ve taken two pregnancy test both at different times and they were negative !!

But my digestive system has been real off, but I’ve also changed my eating habits with healthier food and a lot of time at the gym.

SHOULD I BE CONCERNED? Or just gone it more time ?