Of course, everyone knows that DynaDot is a great registrar. I can't say the same things about the SSL Certificates. I ordered one more than 48 hours ago and I still don't have it in my account or email. On the website it says less than one day. This means a double time than expected, and this could produce big disadvantages.
:( Probably I'll never use DynaDot again for SSL Certificates.
I'm happy with my SSL certs purchased through Dynadot. If you were to buy them direct from RapidSLL you'd get them quicker but you'd also pay a lot more.
Have you received the confirmation email from rapidssl and did you click the approval link in that email? When that is done, rapidssl usually sends you and us the ssl cert soon after.
If you already approved the link, then your website might be under review by rapidssl, though they usually notify us when that happens.