I medically retired in February. When can I expect my first disability check from the VA?

Thank-you for the response; but I've seen a lot of confusion on the issue of "first payment" and I haven't been able to get a complete answer on it, after multiple calls to the VA call center.
You stated Effective date is the day after separation (usually the last day of the month), so someone that separated or retired on 28 Feb, would have an effect date of 1 Mar, and the first payment would be for the month of March, which would be paid on 1 April, according to what you stated above and information on the VA website.
In reality, the VA decision letter (in this example) will have an effective date of 1 March for the service connected disability rating(s) and will have a PAYMENT START DATE of 1 April.
The confusion comes when the first payment comes on 1 May for the month of April and not on 1 April for the month of March as expected since March is the first month the rating was first effective, and 1 April would be the first payment date as documented in the letter.
Calling the VA Call center, gets an answer, that they skip the first month after separation/retirement since the decision is effective on the 1st day of that month, so its not "a full month" and they don't pro-rate, only do full months, and so they start payment effective for the next "full" month which would be April.
The documentation on the VA web-site doesn't explain this situation at all and leads to a lot of confusion for multiple veterans, and so far no one has been able to provide a reference that provided details about the rules for skipping the first "partial month". They say its CFR 38, but nothing more specific, which begs the question where is the statue for this well established procedure?

LtCol Robert Quinter - You're alright with me and with us, Robert!

Yes I chose the VA disability comp as I was rated at 80% which was higher than DOD retirement and the VA payment is tax free. SFC(P) (Join to see)

SSG(P) Loris Metzinger - That's what I figured what most people do when you are rated that high if they don't medical ect for kids. So yes contact the VA you should of already received pay by 45 days.

Thanks brother. I actually just called them and they said my claim should be finished by April 8th which will put me at the 55 day mark. SFC(P) (Join to see)