Can my 5 month old male puppy get my female dog pregnant. They did locked up this morning.

Possible but pretty young for a male. Get him neutered. Actually, get them both fixed!

It is possible, but at this age his sperm will be of low quality and/or count.
The only sure way to avoid an unwanted litter in this case is to have her spayed.
And if you neuter him him soon (6 months is the norm) you will have a happier, healthier pet.