I know you all aren't pregnancy tests, but im looking for some opinions..

So my fiancé and I had unprotected sex on the day <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> predicted ovulation (I dont do anything to confirm it, but i can tell by sexdrive and type of discharge its never far off) and he pulled out on time. We aren't actively trying but if I do get pregnant, we will be really happy!

Its been 8 days since then and since 2 days my breasts are bigger and a little sore. Normally this happens like 4 days before my period, but im still 7 days away from my period today! My period is very regular, so I dont expect it to be an early ovulation/period. This evening I started having light lower back cramps and hardly noticeable cramps down by my uterus.

Could I be pregnant? When can I start testing?