Precum is perfectly healthy & normal. While it's composition is somewhat different than cum, it's functional purpose is to lubricate the urethral canal prior to ejaculation, in order to enhance (facilitate) better mobility of sperm from a male's ejaculations to impregnate a female partner.
Most oral partners find it has a sweeter taste than cum too, making your precum a positive & treasured reward, "inDICKating" you're highly stimulated, healthy and excited to receive a high-quality BJ from them! Precum in quantity is a VERY GOOD (& HEALTHY) THING for BOTH partners, so enjoy yourself!:thumb: