I have been on Labetalol (blood pressure medicine) for the past few months and so far it has been…

I have been on Labetalol (blood pressure medicine) for the past few months and so far it has been great at keeping it down..it usually runs around 120/80.. I take it twice a day,I took it Monday morning and Monday night shortly before going to bed,woke up Tuesday morning and was feeling dizzy so I checked it before taking my medicine and it was 153/100,did the same thing this morning and it was 147/102.. it goes down during the day and labor&delivery; checked my urine for protein yesterday and found nothing

any ideas why it's suddenly spiking in the morning? :(