health insurance

Hey everyone, looking for a little help! By the end of this year I will lose health coverage when I turn 26 and age off my parents plan. My job doesn't offer any insurance plan as its a small business. I know I can buy my own plan and will qualify for special enrollment because of me turning 26, I know I can get insurance but my dilemma is that I'm getting married in May 2017 and can be placed on my now fiancés plan then. If I get my own plan in the fall how long will it last? Is it a month to month thing or yearly? Can I cancel it when I get married to go onto his plan? Would we be better off getting legally married soon so I can go onto his plan when my coverage ends then just having our wedding in the spring? I'm so new to all of this and in a unique situation so I was wondering if anyone had any insight! Thanks!