There is a brand available here, Seventh Generation, (don't know if it is also available in Alberta but probably) that you can get at grocery stores like Whole Foods that sell a lot of natural and quasi-natural stuff. They make a lot of paper-based products including diapers, and I think they make pads. The big deal is that they don't use chlorine in the manufacture (I think). Maybe it would help to try out a product like that.
Pads cause irritation when left on too long. Just because they are not full or do not have blood on them does not mean they have things like sweat, which can cause irritation. I would suggest trying to change your pad sooner than usual if you are getting irritation from the one you are using.
I used Always with no problems unless I left them on too long. Now, I use tampons as it is far less irritable than a pad in my opinion and I don't get the gushing feeling I was able to get with just a pad. I just remember to change them every few hours to avoid things like TSS.