yea , just like the other dudes said. Its totally fine to change it back to veg. A lot of people find their plants sex that way.. Just for future info tho , taking a clone, and flowering the clone after about a week or so once it gets its root system established, is much easier and better imo. That way u can keep the main plants in veg and still easily find the sex.
Just make sure that if ur taking multiple clones from multiple plants, or even just 1 clone per plant.. label them so u kno which clone came from which plant, incase of a male.