Being new to birth control, your body is still ironing out the bugs. It may take you a few months to get adjusted to it. Spotting is typical when one is on the pill. As far as the pre cum issue....that is up for debate. Many say that you can get pregnant from pre cum or pre seminal fluid, other's say you can't. I am on the fence about that one. If you miss a pill, you are deemed "unprotected" that is why you should take your pill every single day and at the same time each day. It doesn't take long for the effectivness of the pill to wear off. If i were you and if you don't want to become accidently pregnant, you have to take it everyday. If for some reason you miss a pill, you can take 2 the next day but don't engadge in sexual intercourse on the day that you forgot. You can take up to 3 missed pills at one time, anything after that you may as well throw the rest of the pills away and use alternate protection until your next cycle rolls around. Even taking 3 missed pills at once may start up your period still.
You haven't missed your period this month have you? If you do, you may need to take a pregnancy test. I don't think that you are pregnant this time. I'm thinking it's the pill messing with you. Just be careful and take your bc every single day.