At 40, would I need fertility treatment to get pregnant?

Maybe. Fertility declines from a peak of 170 births/1000 women at age 27 to 13/1000 at age 40. Thus, advanced age is a significant fertility issue. However, not everyone needs help. See a fertility specialist for assessment (fsh, amh, antral follicle count) and if favorable then try 3-6 mo. If unfavorable then get help now before too late. Once fertility poor we cannot help using your eggs. Good luck.
Not necessarily. At age 40, the fertility rate is lower than for women in their twenties or early thirties. If you don't get pregnant within 6 months of trying, it would be appropriate to get a physician consultation so that if there is a problem, it can be identified early and treated. One thing you can do on your own is to use an ovulation predictor kit to tell if and when you are ovulating.