Problem with blower,,i think

I have an 03 bravada,,had it a year now and love love it.Never had a problem with it till now and I am not sure if it is a problem or what it is..
Ok here is what is going on,Just in the last few months my blower started shutting off.It is very random that it happens though.It has only happened like 3 pr 4 times in 3 or 4 months.From what I can remember if it decides it is going to do it,,then it will shut off with in 15 to 20 minutes after starting the olds.The blower will shut off for a few seconds to a minute and then come right back on. Any one else ever had this happen..
Also when i start the olds the blower does not come.After the olds has idled or been driven a few seconds to a minute or two the blower kicks on,,Is that normal for the bravada?

If the truck has the automatic electronic temperature control, the delay after start-up may be normal. The blower shutting off completely while driving is probably not normal, and may be a blower relay, connection, blower speed control, or failing motor.

If the truck has the manual heat/AC controls, the blower should not delay, and the problem could be any of the above items as well a a blower resistor, blower switch, and high speed blower relay,