I just started the pill yesterday...

I have a question for y'all. I took my first (birth control) pill yesterday and today I woke up to spotting. Is this normal? Also (this is a dumb question) my birth control was (originally) to help with my periods. Will is still be as effective as preventing pregnancy? I had all these questions I was gonna ask my OBGYN but my mom was with me and she's not open to that kind of thing :/. Also how long do I have to wait to have sex?