Discomfort during lately?

For the past week or so my boyfriend and I have hardly been able to have because I keep getting this bad stinging sensation on the left outer part of my . I'm pretty sure I don't have a UTI because I haven't had any problems urinating and neither of us have an STD. We have been using a new lubricant though and we use plenty of it. Is it possible that I may have an infection? Any input would be helpful. Thanks :)