5 weeks pregnant and not eating healthy

I’m 5 weeks and I haven’t been eating healthy. Yesterday I had wendy’s. Today I had checkers. It’s so hard to quit eating fast food. I’ll eat salad and healthy stuff here and there but my diet mostly consists of candy, junk food & soda. I’m trying really hard to stop. Even though I’m 5 weeks and there’s no umbilical cord, Could my baby still already be affected? Will he/she not grow properly due to this? What if i stop eating bad & get on the right eating track?... Is it too late???