How early can you start having pregnancy symptoms?

Caitlin
My long distance boyfriend and I ended up having sex all 3 days that he was visiting me this last weekend without protection except pulling out. One of the days we had sex was on my last 'fertile day'. Its been 5 days since the last time we had sex and I'm starting to feel.. Weird. My boobs are sore, my stomach is upset, and I have this all around weird feeling. I've never had symptoms like this before my period, and my period still isn't for 5 days or so. I've heard its impossible to get symptoms this fast but I'm kind of hoping its not just all in my head 🙈 do you think I could be pregnant? And how early did you start experiencing pregnancy symptoms if you've been pregnant before?