Ortho tri and ortho tri lo are basically the same except that orthro lo has less estrogen then regular. That helps to clear up side effects like pms, and swollen tender breasts because those effects are usually associated with more estrogen. I was on ortho lo and never had any side effects like that, my only problems was I had periods that lasted a week and a half. I'm still on it now, but i'm switching to levlite at the end of this pack.

Lo actually gave me those side effects when I didn't have them with regular ortho. Everyone's body is different and will react differently.
However, the pill is suppose to relieve you of pms, swollen breasts, etc. I think you should switch to a different kind altogether.
On lo I spotted all month too. A real pain in the butt.