Should I be worried ?

My dad woke me up about 10 am yesterday morning and said he thought my cat was in labor. I woke up to find her panting with her tongue out, and she was constantly switching sides that she was laying on. This occurred all day and today it was an off and on kind of thing ? Is this normal ? Is it labor? What are some signs i should be looking for ?

Contact a vet asap, phone at least for advice.

IF it is labor, it seems to be a rather long labor without results, so time to contact a vet and be also ready to rush in.   It is about 20 hours now, yes?

If it it not labor, she is in big pain.  The vet will know which follow up questions to give.

Good luck!

It is not normal, agree with above a vet needs to be contacted asap.

It could be, if it is I'm concerned you don't have any kittens yet - I don't know what local time it is where you are, but 'since 10am yesterday' sounds like 24 hours or so.  If she was mine I'd be taking her to the vets.