One more thing. I just looked at your profile quick to see if you had charted online and noticed your fertility info. If you continue to see a luteal phase of 10 days you may want to have your doc check your progesterone and make sure it's sufficient. 10 days is the very low end of normal and may make it a bit harder for you to get implantation in time before your progesterone drops and you get your period. I did also notice you are trying to lose some weight. This may take care of the problem also. We see women a lot who have weak hormone shifts or weak luteal phase and if they are on the low or high end of the weight spectrum often even 10lbs can make a big difference in regulating their cycle. Anyway. Just something to keep an eye on as you definitely don't want the luteal phase to be any shorter then 10 days.
Although it is ideal to take a temp at the same exact time every day the general rule of thumb is that to consider it reliable you should try and take it with in 1/2 hour either way of your normal temp taking time. The best thing you could do at this point is make notes regarding the temps that are taken outside of this range and keep that in mind as you look at the chart. If there are too many that are WAY outside of range it can be a problem yes. BUT it's still worth trying as it just depends on you. Some women can work shift work meaning days and nights and all over and as long as they take their waking temp after their longest period of sleep they are still able to have a chart that makes sense. It depends on your body. If you would be able to combine what you are seeing temp wise with a cervical mucus record it would also help filter out the abnormal/missed temps. If you get a chart up online either on fertility friend where you can link it, or on one of the charting apps they have on this forum let me know and I can take a look if you'd like. Good luck!
Temping can be VERY sensitive. In order to have any reliability you must temp at the same time everyday. You are not supposed to move prior to temping either, meaning, wake up and reach for the thermometer, some keep it under their pillow, you aren't even supposed to roll over, lol! Lots of people can temp and rely on this, I did it for several months and could tell when I O'd. When I went to see me RE he said to stop just because of the variables that can alter your temp, even a dream can change your results. Anyway, you must be consistant to read your body changes, otherwise it is of no help. HTH!