Gemma - yep.. the babies will still be close. My 2 youngest sisters were 16 months apart and people confused them for twins alllll the time. They are pretty close too... but, then, I am close with my other sister that was born 2 years after me. Could be because we shared bedrooms for many, many years, LOL.
Good luck with it all! It's great that your GP has given you the all clear. Sending lots of baby dust for December!!