Probably only January. You would need to contact your lender. The interest payments would have to be reflected on your 1098 form or else the IRS will send a mismatch letter.
You can likely pay your January payment now. The payment would have been billed in December and is probably due January 1 with a 5 day grace period. If you paid extra, such as for February, the lender would probably apply it to principle instead.
