Still no af bfn

Im getn very anxious cd31 no af 3 days late bfn cramps continuos on my left especially wen i bend dwn last month i had a mid cycle i dnt know wat to think not sure if i ovulated late had cm 3 days after day15 which they say was ovulation i hav 2 kids never experienced this mayb im getn old lol thinkin a trip to doctors this afternoon to put my mind at rest has anyone experienced this??