Hindi po agad late registration if within 1 month lang, kaya relax ka pa! From what I know, you have hanggang 30 days after birth to register for free sa PSA without any additional requirements, pero honestly a few of us moms dito sa group namin nagparehistro pa rin on the 45th day or so and nakuha pa rin nang walang problema, the key talaga is to go to your local civil registry office or the hospital where baby was born at itanong directly kung ano na ang deadline nila because sometimes it varies depende sa lugar at procedures nila.