lower back pain

Yesterday I had some brown spotting throughout the night. Today morning I went for a scan everything came out normal. The doc said it's just old blood which was making its way out. But I'm still scared and going to take it easy for the week. I am still getting some gas and lower back pain. First pregnancy fears! Anyone facing the same. Its my first time and I am 5 weeks 5 days now. 😩😩😩😩