After 12 years together, is he cheating?


We've been married for 9 years, together for 12, and we have an 8 yo daughter, we've had our problems, gone to counseling, marriage classes, etc...but here recently I've been having lady problems. In November I had a UTI and some abnormal bleeding so I went to the OBGYN and was diagnosed with bacterial vaginosis. I went through the course of antibiotics as prescribed and also had to do a course of antifungals for the resulting yeast infection. And now I'm going through the same thing without the UTI and this time the doctor decided to test me for STIs, I'm still waiting on the test results.....what is the possibility that this is all just something that happened? Does this mean he's cheating?