When I was pregnant, I worried about them as well. When I did my research, here's what I found:
Aspartame can be consumed in moderation. It has a risk factor category of B/C.
Sucralose/Splenda: are fine, but keep in mind that these products are relatively new.
Saccharine: has a risk category of C and should be avoided in general. It has a carcinogenic effect, so try to limit it even when you're not pregnant.
I used the book "Pregnancy Dos and Don'ts" by Elisabeth Aron, M.D. when faced with most of these "iffy" decisions and that's where I pulled this info from for you. I liked the way she layed out the information. Everything was in alphabetical order by topic. For "risky" items, she gave an overview, the concerns, and a "bottom line" which I found very helpful when justifying my own decisions.
I wouldn't worry too much about it at this point. All in all, none of the sweeteners you used have a "Warning - Stay Away at all times" label, so you're fine. You did what you had to do to keep hydrated and get through the pregnancy, and that's what counts. Keep up the good work and good luck! You're in the home stretch!