Oral Contraceptive

In February 2009 I went off YAZ, and began trying to conceive. In December of 2009 I gave birth to my twins.  5 weeks later I started back on YAZ . After 3 cycles I had still not stopped bleeding, and switched to Tri-Sprintec. Within a month the bleeding had stopped, and now my cycles are back to normal. The only problem is I would really like to go back on YAZ. My pregnancy weight was almost falling off until I started the Tri-Sprintec, but as soon as I started it I instantly stopped losing weight (even though I’m actually trying now).  So, I was wondering will the YAZ be as effective as the Tri-Sprintec both to regulate my cycles and for birth control? Does Tri-Sprintec typically cause weight gain/ difficult weight loss?