so this is my past periods

they are usually pretty abnormal. well I tried the when to test things, well they do the normal 28 day cycle and when to test and what not, which is

however since my last cycle was 31 days i put in 31 days and got this

obviously telling me to test different days. my chart this cycle has been

help, when should I start testing,I dont want to test too soon and get discouraged,I've had 2 miscarriages and I am trying to stay hopefup bit this is reappy hard, please help, gibe me advice or something please.