After I Finish Peeing, It Starts To Get Uncomfortable. This

After I finish peeing, it starts to get uncomfortable. This feeling lasts about 15min- 1 hour. Lately, it's been happening every time I pee. I got tested for a UTI and it came back negative. I also am sexually active but have only had sex with one person, and my boyfriend (since 7th grade) has only had sex with me, so it can't be a STI. My doctor told me that maybe it's because I am not relaxed while peeing (?) and also said that maybe it's from washing myself with a bar of soap. (I use dove sensitive bar of soap and shower nightly.) is this a normal thing? Is there anything I can do to stop it without making a trip to another doctor? I need some answers because I am rather uncomfortable!