Is it normal i cannot reach orgasm by fingering myself?

Every now and again I will try to finger myself. It takes some effort since I have to contort my hand into an uncomfortable position. My nails scratch my inside, not painful, just annoying and certainly a turn off. Even if I had my nails really short, fingering won't give me any pleasure. Hardly touches the side, literally.
To orgasm, I have to use a toy when masturbating.
If a partner fingers me, it does feel very pleasurable and enjoyable. But I still can't reach orgasm from being fingered by someone else. I would have to have sex with them to reach orgasm.
Is this normal? I've talked to a few ladies about this and I have got mixed opinions.