16 year old boy anal fears part 2

hey guys its me agian . i have been feaking out of my mind for about 4 well know its 5 mounths wondering about this still. i asked her and she told me that she has had all of her periods on time. and her belly has not grown at all. and also keep in mind she is still a virgin. i think im scared still because they say that the sperm can go down out of the anus and near the wall of the vigina. however she has not shown any symptoms of being pregnat . she tells me that she is fine. has i been long enough for here to see signs yet or no? how long does it take for the womans belly to show growth any way. my friends tell me im fine but im worried . i mena like i saind 5 mounths ago i mad sure that none dripped. but still what if after it could have how ever its been 5 mounths should i still be worried. could she still be pregnat? im so scaried