In august I entered the country on my B1/B2 Visa (wich will expire in year 2012), and I got married in October.
A visa merely gives you authority to travel to a US port of entry where an inspector has final decision as to admission into the US. Such is what the I-94 arrival/departure record does with a valid/admitted to date.
THe problem is, my I-94 will expire on Feb 14th.
Anytime in the US beyond the validity of the I-94 is classed as being out of status. If you are out of status for more than 180 days you will be banned upon departure from the US for 3 years. Overstays of more than 365 days face a 10 yr ban.
Normally under the Immigration and Naturalization Act (INA) you may not adjust status (AOS) to Lawful Permanent Residence or change/extend status if you are out of status on the day the relevant application is received by USCIS. However the INA paroles (forgives) out of status where AOS is made on the basis of marriage to a USC spouse. Depending on the place of filing which is determined by residence AOS can take anything up to 3 years (e.g. Texas and California centres) and will often require an interview. IMHO you are likely to get an interview since you got married shortly after entry into the US on visitor status.
During AOS you may request for a travel document called Advance Parole to travel in and out of the US. AP doesn't discount the 180/365 days bans so if they apply don't set foot out of US soil until you get your green card. You should also apply for an employment authorization document (EAD). Make sure you file the petitition (I-130), the AP, EAD concurrently/in the same packet.
The alternative is to go home and apply for an immigrant visa from Mexico aka consular processing but expect a delay of several months in which time you may not travel to the US. Advantage of this method is you enter the US as an immigrant from day 1 and start accumulating time towards US citizenship.
I would suggest you check out on a search engine such as google USCIS and Department of State (consulates in Mexico) to see the timeline differences.
We haven't filled my documents yet (my husband is getting his taxes together and I haven't had my medical examination).
IIRC you need 3 years of tax files - check the USCIS site and see if you can file with what you have. You can get a co-signer/sponser.
I have a chance to go back to mexico later this month. Should I just go without mentioning anything on exit, and just getting a new I-94 on the way back?
You are an intending immigrant and as such your re-entry will if successful be fradulent. The B1/B2 is a non immigrant visa. In any case as soon as the inspector establishes you are the spouse of a USC you will be denied entry. Said fraud can lead to expedited removal proceedings with a 5 year ban from the US - there is no judicial review so don't bother with the 'let me make my phone call' stuff.
I am started to get worried because my husband I will have a large religious wedding in Mexico in June. I worry about not being able to go out/ come back)
Postpone this until you get AP unless you decide to go the consular processing route.