Birth control

Michelle • I`m 24 baby Declan arrived 08/07/2017! I have 3 angel babies.06/18/15 and mono-mono twins on 06/27/16.
I just started my broth control on the 9th of Dec. my bf has came in me the 18th, 19th, and the 22nd three times each day. Am I covered with my birth control I will admit I don't take them at the same time every day. I work nights  four days a week so my schedule is a mess. I'm on the combination pill and my understanding is that since it's the combination pill I don't have to take it at the same time every day. I'm also over weight and the doctor told me the pill could be less effective. Has anyone heard that? And how much less effective? My doctor didn't tell me much detail about that.