Anybody else got the junk food guilts?

I've been eating sooo much rubbish probably in the last month. I'm 17 weeks and have eaten hot, salty chips (my one and only craving lol) every other day, and I feel horrible because it's not healthy like the meals I should be eating, but by the time I get home from work I'm exhausted and just want something easy, which most of the time is hot chips lol. I've only gained about 2.5kg, which is normal from what I've read, but still...
I've made a conscious effort to have steamed vegetables a couple times a week this week (I'm a vegetarian, so no meat) and I always take my vitamins, but I just feel so guilty and worried (especially now my 19 week anatomy scan is booked) that maybe my lazy eating is going to or already has hurt the baby. Is anybody else in the same boat? Anybody ate so much junk and it HAS affected your baby, or was he/she fine??