I was pregnant with my oldest son and due 2 weeks before my exs cousin and it didnt bother me. She ended up having her son 5 days after I had mine and 1 year later I had my 2nd son on her sons birthday. No drama. Birthdays were easier. Considering she had 2 april babies and so did I. It's not a big deal.
My sister had her son 6 weeks before I had mine...we both love it! We can compare what they're doing, and talk about "little babies" all day. She has 2 older ones too, but it's so neat having LO and his cousin so close in age. I love it