Swifts, Swallows (?) Flying Back and Forth

Just arrived home after a longish walk. Was cutting across a field when I noticed a low-flying, swooping bird that kept flying back and forth in front of me - always about 5 metres in front. I think it was a swift or maybe a swallow - I'm not too au fait with birds. Either way it had pointy features and kept swooping close to the ground. This is about the third or forth time I've experienced this sort of behaviour with these birds and I thought it was something worth making note of. It definitely seemed to be deliberately flying in relation to me, almost circling me at times. Why I don't know. A brief internet search turned up nothing. I live in North Yorkshire by the way if that helps with the birds identification.