Before planning children, you should take into account the possibility that you might somehow end up being a single parent. I know, you do not really want to hear that but you should be ready for everything. Just in case. And you should perhaps ask other single parents what it is like, because only they will tell you the truth. And you need to know the truth. Not things that are shown in movies. Because when you are a single parent, you have to prepare for it to be a full time job. Your kids will need you all the time. And you will probably not have the freedom to make your own plans. Like, for example, a date. Just let´s not forget about the fact that every new partner would need to be approved by your kids. 
Also you will probably have no privacy and there will be times when you will want to give up. Or scream. But still, it is all going to be worth it, so do not worry! You can do it! 