Still working on my first batch, a BB American Light that my dad and I started this past Sunday. OG was 1.045 when I pitched yeast. Then fermented at 70-72 degrees. Took a reading today of 1.010. While racking into a secondary, I noticed air bubbles in the line with the wort. It started at about the half way mark and became more prominent as we got to the bottom. Is this normal??