Pregnancy

Can anyone give me some advice? I’m 18 and started taking birth control about 2 months ago, but I’m over two weeks late on my period. I’ve taken 5 pregnancy tests since my missed period that have all came back negative but I’m still worried because I haven’t started yet. I’m afraid to ask my parents to take me to the doctor because I don’t want them to suspect I’m pregnant. I’m not sure if I should be worried or not.