I turn on the water in the house and it runs fine for a minute or two. Then, its slowly starts to decrease like there os not enough pressure or it is running out of water. I turn off the tap, wait a few minutes, and cut it on again and it rums like nothing happened... any suggestions?

More details please! How old is your house? What type of pipes? Copper? Galvanized? Plastic? Does the pressure drop all over the house?
When the pressures falls have someone go out and see what the gage reads. Let me know, Tom

I'm not sure how old the house is... I know over 10 years but how much over I'm not sure. The plumbing is all pvc and the problem is not isolated to one area but affects the whole house. As it does not happen every time the water is turned on and only happens for a few minutes I have not been able to look at the gauges while this is happening to know whether it is an actual drop in pressure or some other problem. My fiancé insists that this is not a plumbing issue and does not think it is severe enough to call anyone on yet, but as the weather gets colder I'm concerned that we will have more issues if this is not resolved. I was hoping to try and repair it myself and save a 100.00+ service call if possible but I have been unable to figure this out.

To help we need all the information we can get. Have the boyfriend go out to the pump and get a reading on the gage when this is happening. To repair a problem you first have to isolate it. I need to know where to start looking. The pump or your house. And yes! This is , indeed, a plumbing issue. Back to you. Tom

This is the first day it has done it since my original posting. The gauge on the pump read right at 50 when I checked it. The pump was making a noise like it was trying to cycle on but it never actually came on... a few minutes later when I came back in the house it was fine.