Only pleasure. Many women report that orgasm reduces cramps.

I usually only do it in the shower when i have my period,although my soon to be ex husband did like to have sexual intercourse and give me oral when i had my period.I didn't mind it made him happy and was a pleasurable experiece for me.I just didn't like to kiss him after he had gone down on me during those times

Some females can orgasm quicker from clit stimulation during their periods. It will be different for everyone