The amount of time you've spent with a person NEVER holds weight as a determining factor in the status of a relationship.
What should be factors for consideration with regard to making a decision to get married are:
- Emotional bond
- Level of trust
Do you know things about that person that you don't like, but still love the person anyway? Have you successfully had an argument and do not hold any lingering resentment or hostile feelings? Are you seeking a marital bond because you want to spend your life with that person, or because you're afraid to spend your life alone (you can't be truly happy with someone else unless you're truly happy with yourself)?
Too many people take marriage and mate selection as casually as they do choosing what pair of socks to wear each day, so if you're serious about getting married, give it serious consideration.