Adding fruit at the start of fermentation will result in most of the fruit aroma being driven off with all the C)2 being generated. Fruit should be added (to either primary or secondary) after most fermentation is done to help preserve the flavor and aroma.
Generally a week is too short. I have some beers that take several weeks to finish. If you bottle before it is done, you will get gushers, and might get bottle bombs.
I use a plastic turkey baster to take samples. Sanitize the baster (put in sanitizer, if none available, dip it in boiling water). I use it to fill my hydrometer jar, check the gravity, and then drink the sample.