I need a few opinions?

My gf went away to a neighbouring country with a mixed group of 15 people on a business trip. It was run by a supplier company. They went in cars(about 4 ) and the journy took 5hrs approx. I did ask that we keep in contact on the phone, there was no problem with that on the journey there. But from that night on she had problems talking to me on the phone, She would not answer my calls when i rang at night when business was finished. At times she would call me back 30mins later and always had some excuse to keep the calls brief. The day commimg bac, what should have been a 5hr trip turned into a 12hr one, and i was a bit worried, the drivers are mad here. On her return the first thing she said was ... sex is out for a while, i have thrush and i'm sore, i got it on my first night there. She said she was tried travelling and went to bed and slept for like 12hrs. Beinf a good bf i organised her washing. Her used underwear was destroyed. She took 8pairs of knickers for a 5day trip. I found 6of them all very gooey from"the "thursh"of whatever, some were still dampish. One pair i found, a red pair were stuffed into the sleeve of a red shirt. All the stains seemed to be centered around the clit area. Now ive seen her get bouts of thursh before, but never with that amount of discharge. Ive seen her knickers after she has gotten pretty aroused and it looked similar. I did ask her, given the problems with calling her and the state of her knickers if anything went on. I could deal with it like an adult. But she seemed shocked i would ask, and got a bit defensive, so i just gave up and made the best of her being back. I'm still not happy that something did not happen. Am i right to be suspicious. I'm sorry this is so long winded. Should i be worried?