pain masturbating??

So I went to a sex shop with some friends a few weeks ago and brought myself a dildo, but any time I've used it it's been mostly uncomfortable and even slightly painful, mostly right up around my cervix?? The width isn't a problem.
I'm a virgin and I'm worried that sex with my SO with be unpleasant since it's just a bit smaller than he is. Is this normal? Will it get better over time?