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I am a non-eea family member of an eea national(which is my stepmother) living in the uk for more than 5yrs now and wanting to get married but will i still be able to use my current residence card after getting married(my fiancee is on a student visa)
what other options do i have available?

We need more information about your situation.
When was your RC issued? Until when is it valid? Under which visa were you before in the UK?

The reason I'm asking it that after 5 years in the UK under EU rules, you acquire Permanent Residence status and are not dependant any more on your EU sponsor.

My first RC was issued in 2005 for a year then another was issued in 2006 for another year then my present one was issued in 2008 which is expiring in 2013

If your fiancee has sufficient leave and can wait, then it may be better if you obtained confirmation of PR first, before getting married.

I presume the first two were Family Permit (which used to be valid for 1 year) and not Residence Card (Which is valid for 5 years).
Have you been living in the UK without long breaks since 2005? What has your stepmother been doing since 2005? Does she work?

Depending on your answers, you might have been automatically acquired a PR status. If this is the case, you can also apply for British citizenship if you wish (if 6 years have passed since you come the the UK).

the 1st two were family permits and my stepmother worked for a while but she's now out of the uk although she still comes frequently and ive not had any long break as ive been working ever since.

Follow vinny's advice and apply for confirmation of PR status using form EEA4. You will need your stepmother passport/national ID card when applying. You will also need to show she has been exercising treaty rights for 5 continuous years (working/retired etc.). Doesn't need to be the last 5 years. Read the form and the guide for the other documents you will need to provide.
It takes about 3-4 months nowadays to get the confirmation of PR.