Conceiving Question

Lakin
My husband and I aren't really TTC very hard, but if it happens it happens. We have a daughter who just turned one on Monday, so part of us wants to go ahead and try for #2, but if it doesn't happen right away, that's okay too. My question is:
We had unprotected sex last Friday, and he wasn't able to pull out in time. One of my other apps says it was during my "fertile" window, and I've been extra tired, having back pains, etc. all symptoms I had with my first pregnancy. Is it too early to tell if I'm pregnant. My <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> says I'm not suppose to start till tue 23rd.