Late.....

I came off the pill just before Christmas and have been ttc since unsuccessfully.....I took two pregnancy tests one on the day my period was due when I was late and another a couple of days later but both were negative......I'm 5 days late now with no sign of my period. Has anyone else found this to happen after coming off the pill? I was thinking it's just messed up my cycle even tho my first few periods were pretty normal. Not sure wether to take another test or keep waitng!