16 DPO: Offically 4 days late

May

So I'm offically 16 dpo, 4 days late I've taken test once in the morning once at night for the last 2 days and all negative. If I were pregnant would my test be positive by now? Should I have my blood drawn? I am always on time, always start first thing in the morning. We've been trying for 2 years now.