Hi Ruald,
If you and your fiance are planning to get married in Spain in the next three months or so, you could apply for a prorroga. This is a visa extension. I applied for one last year and was told they only grant them for “extraordinary circumstances”, which includes plans to get married in Spain in the near future. I say 3 months because usually they will only grant extensions for an additional 90 days, though in some cases they will grant them for up to 180 days. You would need to apply for the prorroga before your original visa expires (preferably at least 3-4 weeks beforehand) and you will need to prove that you have set a date for the wedding. You would then request an extension up to that date.
Even if you do not have a set date yet, you can apply for the prorroga. It usually takes them at least 1-3 months to process your request (depending on the volume of requests they have, I assume). During that time, they are holding your passport, so you cannot leave the country. And since you are “en tramites” you are legal. So even if they reject it, you are legal to stay in Spain until they tell you so—and that could end up being a few months. The thing is, if they reject it, you have 3 days to leave the country. If you don’t, you could have problems in the future if you apply for a visa. If they reject you and you abide by the 3-day rule, it should not affect your future visa requests.
Good luck!
Kronos
http://www.allthingsspain.net
http://eslhell-thepaininspain.blogspot.com/