Cliff Hawkins/Getty ImagesLindsay Flach, 18 weeks pregnant, announced via Instagram Friday that she will compete in the U.S. Olympic Trials for the heptathlon.She told Jeff Eisenberg, Yahoo Sports, that it was difficult mentally because I knew I wouldn't be able compete at the same level I was capable 18 weeks ago. But she said she wanted to prove women can do anything. "It was incredible to end one chapter and start another on my terms.Flach stated that she discovered her pregnancy in March, and asked her doctor if it was safe to continue her training. The doctor gave her permission to continue training in moderation. She also asked that she avoid falls and be aware of any warning signs her body might give.She said, "My main concern was to make sure I was healthy" and that the baby was well.She stated that her pregnancy was not easy.Eisenberg was told by her that "my pregnancy was very difficult to begin." I had 12 weeks of severe vomiting that affected my training. I'm not sure if the Olympic Trials had been three weeks ago. But I felt better and was able to do some really good practice runs.Flach, 31, had planned to pursue a spot on the United States Team one more time before she started a family with her husband. Flach was determined to pursue her dream, even though the Tokyo Olympics were postponed by the COVID-19 pandemic.Flach said that it was bittersweet to learn she was pregnant. "I was excited because I have always wanted children, but it was also shocking to know that my track career was over."Flach wanted one more chance to compete, but she wasn't able to do so at the Trials.To avoid falling, she modified her steps to get through the hurdles. To ensure that she didn't injure herself, she cleared the high jump at one height. To avoid being overly tired, she ran the first 100m of the 800-meter event. Eisenberg said that she didn't take on Sunday's extreme heat in Eugene. She made only one attempt in each shot put and long jump.She was last. She was the last to finish.