Wondering when too apply for maternity grant/child benifit

Hi guys.. I'm 14+1 weeks pregnant and just wondering when's the right time too apply for my sure start maternity grant & when too apply for child benifit? I am now on income support so I know I will be entitled. Havnt told the job centre I'm pregnant yet as I'm not sure of they'll dismiss me because I'm only 14 weeks? Someone help! Thanks