How early can you start to have pregnancy symptoms?

What are your early signs of pregnancy? my last pregnancy I had none except I couldn't finish a drink or smoke a cigarette (we weren't trying to convieve otherwise I would not be drinking and smoking). I'm hoping this time im not imagining things but I felt a little sick waking up this morning but disappeared after 5 minutes. is thrush an early sign? for the past 2 days ive had a mild case. and my skin is sort of breaking out but there little break outs a painful my usual pimples don't hurt. and I feel like my fuze is very short and everything annoys me. I could only be 2 or 3 weeks pregnant that's why I'm confused to have symptoms so early???? also my tummy turns (no gas) and I've been drinking a lot of water but still not doing number twos sorry for the personal info but were all girlies:)