You were another android made by Dr Gero along with Android 17, 18 and 16. However a Bio-Android named Cell came from the future to absorb 17 and 18 to become perfect. When your brother 17 was fighting Piccolo who Fused with Kami. You noticed them all looking at a weird bug like creature. This is weird.

Cell: "Ah hello again Piccolo. And if it isn't my dear brother and sister. 17 and 18. You two will be absorbed so I can become perfect one way or another. Seems we have some unfamiliar faces. So I guess I have more siblings."