As @GoddessEpona said, a familiar chooses you, not you them.
That said, if don't feel you have one that came to you on its own, I see no harm in placing a request for one to let it be known to potentials familiars that you are looking to work with one.
Now, onto your original question, if you feel the spell didn't work, then it probably didn't work. Give it some days to be sure, and if you don't sense that a familiar has come to you, try placing the request again.
Don't be pushy, though, spirits are not obliged to answer you and do your biding.