Help a newbie...

June was our first month ttc, looking for some advice please. I ovulated on CD 17/18. Today is cycle day 31 and 13/14 dpo. The witch should be here tomorrow but no signs, nada, nothing that she's coming. Bfn yesterday...should I wait a couple days and test again? Anyone test negative at 13dpo but have a positive a couple days later? Help a newbie out, trying to sort though all these days and what to expect. Since I ovulated a few days later in my cycle maybe a bfp will be a few days later than normal!?