Effects of antibiotics on birth control and becoming pregnan

hi, this is all new to me but I am wondering if anyone knows is amoxicillin really makes birth control ineffective? I had to take amoxicillin 2 times this month and am on yasmine. I got my period 2 days late and when it came it was alot lighter than usual and onl lasted 3 days. I heard that if you become pregnany on birth contril it tends to cause bleeding during early pregnancy, is that true? I also have had several pregnancy symptoms like cramping, feeling sick, tired and weak and sore breasts. Could i be pregnant?

Well it's probably possible that you could be pregnant but if the antibiotics make the pill uneffective then it could be the same as stopping the pills and your body could have been acting this way (cramping et.) because your body is coming off of the pills (since the antibiotic might have been messing it up). Did the doctor you got the antibiotic from know you were on birtth control?

no, the doctor didn't know i was on birth control. And i just looked it up online and it says to keep taking birth control when you are on antibiotics but to use a 2nd form of protection for 2 weeks because it cancels out the effect.