Hi I'm 36 Years Old Been Spotting With Occasional Brown

Hi I'm 36 years old been spotting with occasional brown discharge, urgency to urinate & some weight gain. My last period was 3-3-2016 & before it was on 2/6/2016. I went to doctor almost 2 weeks ago, had vaginitis bacterial infection but no STD'. I wondering if I could be pregnant? I've had 2 children 18 & 10. Spotting is not the norm & my cycle comes every month regular