Thats completely normal, dont forget at 25 weeks your baby is still tiny, I am 30 weeks pg with twins and depending on how the babies are lying I still only get movement on one side sometimes. Wait till you get near the end and feel baby doing a full on somersault lol
I expect your little one has curled up on your left for the time being but will soon be moving all over the place
Congratulations and good luck with the rest of your pregnancy x
26 weeks pregnant (2nd time round) and feel exactly the same only on my right side. I did ask my midwife if this was normal, because up until about 2wks ago, the movement was very low down. She assured me it is absolutely normal, it may be that the placenta is lying on my left side therefore no movement felt there.