Yasmin does infact cause a woman to need to pee more often. I'm not totally sure why,though. I don't believe ortho-cyclen or ortho-tri-cyclen cause a woman to need to pee more, it's not a normal side effect, but it's possible that it could. I pee constantly, everything goes through my system very quickly so if i have a lot of liquids during the day, i pee a lot.
If you started the pill on the first day of your period. You are automatically protected under the pill. If you started the pill the sunday after your period started, you need to wait a week before the pill is effective. If you started the pill on a random day, not a day you were on your period, you need to use a back up for at least two weeks, but to be safe, probably a month.