Also consider where a 3.7 puts you in your class.
Even though your school does not rank, colleges will know where you are in your class both by comparing you to other applicants from that school and by looking at your school profile. The school profile will generally have the GPAs earned in your particular class year, and is usually broken up down by quartile or decile. So, by looking at that, they will be able to tell if you are in the top 10% of your class, the top 50% of your class, etc. This is generally very important information as it helps admissions officers compare GPAs, which are really irrelevant out of context, across different high schools. A 3.7 at some schools may be top 15%, while at other schools it is bottom half. The school profile will tell them that.