Ive heard mixed stories. ive heard bad because they will not get the individual attention they need, and ive heard good becassue they will be able to relate to eachother and look up to each other. i think we will have help from his mother as well, so that is a bonus when having so many kids close together. I am not pregnant yet, but I would like to know this for future planning.
Re: We both want 5 kids, right in a row. Bad or good idea?
My advice, take it one child at a time. Each pregnancy is different so after your first pregnancy your body may really want you to rest and you may reconsider. I am having my 3rd child in the 3rd year and its not easy but not impossible.
I do make one on one time for each of my babies. And then I also teach them about sharing me, their dad and their toys. Its also important to have a hubby that is hands on. I am also very lucky to have tons of family and friends nearby that can drop in or take the kids if I need a day off, or if the hubby and I want some one on one time too. That is very important for any marriage.
Also, financially it does get hard but I have found ways to cut useless expenses and we actually spend less than before when it was just the two of us and we still have money for luxuries like trips and such.
Do you have any children yet?
Plans are good to have but the beauty of a plan is that it can be revisited.
Set goals but take a serious look at how your marriage and lives are faring after each child before deciding to continue down that path.
The first year of a newborn is really hard on my marriage.
Doing that back to back 5 times would have brought us to the brink.
There's no way to know how you're going to do as a couple with children until you're living it.
ETA: Your bio says your wedding is more than 2 years away.
One thing at a time, Dear.
Focus on building a solid foundation for now and revisit this subject closer to the time to implement the plan.
Total score: 6 pregnancies, 5 losses, 2 amazing blessings that I'm thankful for every single day.
Ditto this. Of course it can be done, and the pros and cons of family size/spacing are usually pretty specific to the individuals. However, I think most would say that the idea you have in mind is a tough road. Make sure your marriage is rock solid first. Enjoy being husband and wife for at least a little while. Then, as a pp said, take it one child at a time.
GL.
I'm the second oldest of five kids - we were all born over the span of 7 years and 2.5 months, so I'd say we were all right in a row.
 I loved my childhood, and I love all of my siblings. I don't feel like I was cheated of any one-on-one attention. I loved that I had built in friendships despite the many moves my family made across the country while we were growing up. But, my parents divorced when I was a teenager. That may have happened regardless of how many kids they had together, but I feel like I should mention it. I'm sure it was difficult for them to find time for each other amidst all the chaos. 
Like other posters have said, I'd take it one kid at a time and see how things go. Good luck!
Joe and Ashley ~ June 16, 2007 ~ Olivia Rae ~ May 12, 2008 ~ 9:06 pm ~ 8lbs 4oz ~ 20.5 inches ~ Miscarriage of twins ~ April 16, 2009 at 6 weeks. ~ Surprise BFP 6/23/09 13DPO ~ Eleanor Rose ~ February 18, 2010 ~ 6lbs 15oz ~ 20 inches ~ Caroline Ruth ~ February 19, 2013 ~ 6lbs 12 oz ~ 19 1/4 inches
Our family is complete!
This! Work on #1 first, then decide when it would be best to have #2, etc.
We have always said 5-6 close in age.... as we began working on it (fertility treatment, ect) the numbers have gone from 2, to 3-4, to after this one we will talk about it.... we are ready for number three, but after that who knows.
One at a time, and plans can be fluid!
As cliche as it sounds, having a baby changes everything. It's definitely important to take it one baby at a time and to take stock of your life and your marriage before adding another to the family. Don't get hung up on the number of kids you want. Plans change, circumstances change. Just take each day as it comes. You'll end up where you're meant to be.
Enjoy your time now with your fiance and focus on your upcoming marriage. Most of all, have fun!