First time for everything......still nervous

So this is the first time I've written a blog...first time for everything but doesn't stop you being nervous though does it?
How strange does that sound? 33 years of age...had 3 children and starting  my life again with my 2nd husband, having another baby....yet I'm nervous of starting this blog.
Feels a little bit like you do the first time you start somewhere new....school, workplace etc...wondering what if people don't like you? what if I say the wrong thing? because quite frankly I have no idea what I'm doing lol.
So if no idea what I'm doing why have I started a blog? good question. I've heard of blogs and thought it sounded interesting...not only that but I feel like I am literally starting my life over again and it seemed maybe a good way of documenting my journey.
 I have 3 children 12, 9 and 6 and now am having another baby with the love of my life. So many people say you know what you doing ..you've done it before and I have...how ever so much has changed!
I'm older for a start, so when I see some mums at my daughters school I feel really old. Not all but some arrive to drop their children and it feel like a fashion show some mornings...seriously. Some of these mums are dressed so immaculatley that I wonder what time they actually get up in a morning....their hair is immaculate, full make up on, dressed fashionably with heels that I would have thought should carry health & safety warnings.
I'm left wondering if I'm a bad mum rolling out of bed at 7am begrudgingly getting dressed to then proceed to get my daughter dressed and ready for school. Some times I straighten my hair but that depends on how tired I am..same goes for make-up..not a make-up person to be honest but sometimes I feel a little better with a little mascara and eyeshadow on.
So now I've given a nervous rambling....I'm going to press publish and hope that I've not gone totally mad and rambled so much people are thinking I'm in need of sectioning.