God there's some shit replies on here!
OP of course YANBU but they are,if someone tried to get intouch with me that early I'd age by about 10 years because I'd think something awful had happened to one of my family or friends!
Who in they're right mind texts someone at 6 in the morning,let alone texting a heavily pregnant women that has children!
I had a friend that used to do that,he always had some emergency or needed to speak to me,he'd text me late at night,in the middle of the night,6 in the morning.I have 5DC and a DH and 2 of our DC are autistic.I talked to him about it till I was blue in the face but it didn't stop so I ended the friendship,I had to,it was just to much and it was constant.
Like other posters have suggested have a look at your phone and see if you can sort out those texts not coming through.
I can't believe how many people suggested turning your phone of either,madness!Me and my DH have to keep ours on through the night because I have an elderly Father who's health isn't great and were hours away from my Mil and Fil and they need to be able to contact us as early as possible if they need us for an emergency,FIL has already had prostate cancer,so we don't take any chances.