how can i get pregnant besides the obvious answer?

“Several months” is not a particularly long time - even if some of the exaggerated scare stories suggest that a girl will most likely get pregnant if she lets a male, so much as, touch her in the right place (or even: “any of the wrong places”, if being advised by one’s over-protective father, chaperone or maiden-aunt).

Anyhow, at your age, I do not think it should even start to become a cause for concern until you have been trying to conceive, unsuccessfully, for over a year.

There is, for a variety of reasons, an increased incidence of “low sperm count” problems amongst modern males, so there may be “fertility problems” with either you and/or your fiancé.

Eventually, assuming your failure to conceive becomes inexplicably prolonged, it may be prudent for you both to undergo fertility tests, after which you can be properly advised about the best course(s) of action, regarding which form(s) of “fertility treatment” could be expected to be most suitable for you as a couple. [ See link below ].

In the meantime, I suggest you both do all you can to improve your fertility: by eating a good healthy, balanced diet, and getting adequate exercise in order to maintain (or get to) a healthy weight.

Also, you should avoid the known health risks such as smoking, alcohol, and the use of illicit chemical substances.