If you are worried or feel threatend, you can always cast a banishing spell and then a protection spell.
As for the spell it sounds like a coincidence to me, I used to message my friends and they'd see the message, but not respond for days, it could be she just finally responded. Most people are against love spells because it messes with the persons "Free Will" and that makes it the love not real. Have you tried talking to her? Explaining how you feel? If she doesn't feel the same then move on. However if the spell is working and it feels like real love to you then you should be happy :).