Has this ever happened to any of you

So I started amoxicillin Tuesday night due to what my dentist thought could be a wisdom tooth infection took them up until Friday when I was able to see him and he confirmed it wasn’t a infection he said I could continue taking them but that day I already had cramping and upset stomach and nausea like If I was catching a bug I was able to pass tmi a few farts with somewhat watery smudgy poop so I decided not to take them well yesterday I just kept having like period cramp pains and nausea and just overall gas and bloating discomfort even my back was hurting so I went to the er and they did an X-ray and they ran urine and just your regular blood work and he said everything was fine as I thought it was my appendicitis since I was having really bad cramps and I had no idea that happened with gas and constipation that bad .. that it would make me feel nauseas and hesistant to eat but he saw trapped gas and he asked if I was usually constipated and able to pass poop easily and I said every know an then so he gave me Bentyl and dulcolax for me to pass some stool but I’ve taken This antibiotic back in November of last year and never had this side effects 🙄 but how long does the antibiotic effects where off