Hi there and big congrats on your pregnancy!
I have just had (well, 5 months ago) baby number 3 but would definately like to extend to 4 in a couple of years- the other 2 are 12 and 6 years old.
At the end of the day- this is YOUR family and whoever thinks that you should only have so many should mind their own business! As long as each child gets time with you and your partner that's all that matters.
Hope you get over sickness soon, I was fairly lucky with my pregnancies- just felt tired! Only had mild sickness with the eldest and that was only when I was hungry, and it subsided after 1st trimester.
Lou x