No. The lease you signed must include certain mandatory information, including the effective date and the duration of the lease, as required by Article 3 of Law No. 89-462 of 6 July 1989. In most cases, the effective date is the date the lease is signed, not the date of physical entry into the premises. If this is the case, the lease has already taken effect, and you can no longer withdraw. You must therefore terminate the lease and comply with the notice period.