(OSV News) — Dr. Marguerite Duane didn't know about fertility awareness-based family planning until she had finished medical school. When she learned by happenstance that there were natural and effective ways to track a woman's cycle, she was shocked. "Why didn't I learn about this in medical school?" thought Duane, who at that point was 29 and in her medical residency. "Why didn't I learn about this in college? Why didn't I learn about this when I was going through puberty and starting my cycle?" Today, Duane has devoted much of her career to educating medical professionals about natural family planning, or NFP, which also can be called fertility awareness-based methods, or FABMs. Duane is the co-founder and executive director…