BBT questions

Ashley • After 22 months of trying Hubby and I had an IUI which helped us welcome the sweetest baby boy Oliver on 10/6/16
So only during TWW I must get excited to see what my temps are because last cycle and this I naturally wake up around 2:30-3am and take my temp I swear I hear the alarm to get up but obviously not at that time 
Question is if I sleep well for 5 hours at 2 am take temp then have off n on sleep till 5:30 take temp which temp is the one to chart??? I usually take the 5:30 one however the 2:30 one was 97.90 and 5:30 was 97.73 big difference