Is an hcg level of 145 normal for 4 weeks pregnant My first beta was Friday and it 40 we did again today Monday is this normal?

The levels seem concerning because your hCG seems low for 4 weeks of pregnancy and did not double since Friday. However only serial labs over 48-72 hours can diagnose whether a pregnancy is not viable. An ultrasound can also be beneficial especially if you are beyond 5-6 weeks based on LMP.