No reviews aren’t necessarily a red flag. The provider could be new or may not welcome being reviewed. You are doing the right thing by asking them if they would appreciate a review prior to writing one. As far as knowing if you are being scammed. If you have visited with this person a couple of times without problems then you should feel safe with them. If they start asking you for things beyond payments agreed upon or if the service changes then perhaps wonder. As of now it doesn’t appear that there are any red flags. Use your common sense, intuition, and read through this site. Lots of helpful information here. It is also important to research each person you are wanting to meet. Look for their social media, website, ads. Google their phone number and their pictures. If they allow a conversation before meeting ask them any questions that you may not find answers to on their ads or websites.