Normal. I've started a new game, and now I'm doing much better. I think my primary issue was that I didn't get my speederbike armada STARTED until week 3, by which time the UFOs were too big and too numerous to be threatened by a baby swarm.
Now I've invested much more heavily in my biker fleet, and I'm downing loads more UFOs. I have some days where I kill one UFO, immediately investigate the other's target, and then everything is calm until the next UFO appears.