A good rule for feeding is: Every 5 days until 100g in weight, then every 7 days.

We'll have to know all the specifics of your setup:
What type of enclosure? (tank or tub)
What the temperatures are?
How you're measuring those temperatures?
What the humidity is?
What substrate you use?
What your heat source is? (UTH, heat tape, lamp)
How you control that heat source?
What food you offer to the snake?

I know I forgot a few, but you get the idea...we would have to know everything about the setup to rule out husbandry issues as a cause of non feeding. Other possible causes are parasites and sickness, or simply a winter fast. It could be almost anything, so the more information you give us, the better we can help you out.