BBT question

This is Cross posted from the bbt board because I’m getting absolutely zero responses over there and hoping someone here might be able to give some insight!

Our son just turned 1 and is hitting a weird sleep regression after months of sleeping through the night, his new witching hour is about 3-3:30am 🤦🏻‍♀️. He doesn’t always do it but it’s often enough that I can expect it a couple of times a week at least. We are thinking of starting TTC at the end of the year so I’m temping a few cycles to get familiar with it again before we officially start. It usually takes about 20 minutes to put him back down, so I’m back to bed by 4. Then I’m up by 7-7:30 every day so I’m kind of afraid that getting up with him might jack my temps too much. But I don’t want to set my alarm for 3:30 every morning and temp then because I’d honestly rather be dead than wake up at that time if baby is not going to be waking up 🤣

Sooo my question is this: if I get back to bed by 4 and temp around 7-7:30 when I wake up, would that be enough time for my bbt to return to its resting state or is that too close? Even when my husband gets up to put him back to sleep at 3:30 I’m still wide awake and I know you’re supposed to temp upon waking 🤷🏻‍♀️

TIA!