My period varies 25-30 days. Lately I am spotting (light pinkish) 7 days before my period. In my last cycle, I spotted on 15th and 16th day of my ovulation. Should there be any concerns about my preg?

Period and pregnancy. Probably not, but have a serum Progesterone level checked as soon as your pregnant. It should be around 20 ng/ml, and if lower start vaginal progesterone. I have helped many women deliver normal kids simply by augmenting their levels.
Maybe. This may be an indication of low hormones values which can reflect poor functioning of the ovary. Or it could be a polyp causing bleeding. Not a bad idea to see your doctor for a quick evaluation.