Spotting after a speculum exam with cervical polyps is usually normal lah, especially since the doctor was checking the area, a few of us mums with polyps during pregnancy had the same thing happen after our appointments, and it settled down after a day or two. Since you're not having cramps or pain, that's a good sign, but do give your doctor a quick call just to confirm everything's okay, especially since you're pregnant and they'll want to monitor it to be safe.