can I be pregnant?

my boyfriend I talked about having a baby. We have started our journey of trying to have a baby and had sex one Friday the following weekend we had sex again but this time when I woke up and went to the bathroom and I was spotting and cramping in my stomach and pelvic area for a couple of hours. I haven't had anymore cramping since then and that was it. do anyone think we could have messed up getting pregnant from the first week. Or do anything one think it could been the start of fertilization.