i think yes it is up to you!
We ttc and fell preg #2 when DD was 7 months.
We are very happy to have them close together.

We get comments (mostly strangers - family are supportive) of oooh they will be close.
And i say.. yes we planned it this way and it usually shuts them up.

i didnt want to be pregnant forever lol.. and so would rather go gung ho and pop them out so they are close in age and DH and I can get our careers and lives back on track sooner rather than 10 years later (if there was a big gap).