Rightio, I'll respond in order!
ThePig: Thank you for your frankness. It's exactly what I was looking for. Yes I think it would mainly interest friends and family because they know me and care about what I am going thru. But as for wanting to reach a wider audience, well the main reason is to help people. That might sound arrogant but I mean to show other people who maybe in a similar situation to me that it's ok to feel scared or negative or exasperated or excited or whatever. A couple of years ago when my first son was just becoming a toddler I discovered this blog: reciperifle.blogspot.co.uk/
I loved it because it showed me that someone else found having a toddler a struggle and boring and things. My blog (which i started last year) was initially a tool to help me lose weight and not really about being a mum. And it helped me stay focused. I changed it when i became pregnant because my first pregnancy was awful and i remember thinking at the time that i would have loved to have known that someone else was experiencing all these horrible things that i'd never previously heard of....SPD/Cholestasis/Pregnancy Asthma/random nosebleeds and/or permanently blocked nose etc etc. Plus being a bigger lady I had problems finding things like maternity tights and stuff that fit me so i thought other people might like to read about my trials and tribulations.
Of course there's the other reason for wanting more readers, which I think is motivation for some if not most bloggers, and that's some kind of recognition...whether it's for your lifestyle choices/your writing style whatever. It's flattering to hear people say they like your blog and I can't deny that that appeals to my narcissitic side! 
Back to your advice tho, too many caps and !!!!....well funny you should say that, my husband hates it when i type like that. In fact i've just had to delete and re-write half of this reply because i automatically write like that! I'm quite an over the top person (which i think probably comes across) and i think that the caps and !!!! represent that. But I can understand that they are annoying to some people so I will try and reign it in.
Tighter theme, hmmm am not sure about this. My general theme at the moment is just the pregnancy, I'm quite happy with just trying to reach an audience interested in that really. But I'll will put some thought into it.
Thanks so much for taking the time to write. 