Pregnancy scare

Okay I need some help😰 so I have an IUD and I was on an antibiotic for a week and was ovulating that same week. Well I forgot about the antibiotic could affect my birth control and my boyfriend did not pull out all week... we had sex 3 times. Well since then I have spotted and that’s it. Normally my periods are normal but I am 5 days late and been experiencing pregnancy symptoms.. so I took a test today after work and there were two lines right away and I left to gather myself and grab my phone (took maybe a minute) came back and the second line was gone.... what do you guys think.