In the finale of a drama called お天気お姉さん, around 8:26 in, I saw this subtitle:
But the pronunciation of 一ヶ月前 sounded either like いっかつまえ or いっかすまえ to me, with no sign whatsoever of げ. The two speakers in the dialogue are male and both have pronounced that word the same way. One final detail I can add is that I've noticed quite a bit of 関西弁 spoken in this. Is this slang? A regional dialect? I can't find any info about this kind of contraction.