Hi Lovinglife! Congratulations on your pregnancy! At this point worrying cannot change the situation so do not cause yourself unnecessary stress. You most likely are fine and your doctor will verify that when you see him/her. During my first pregnancy I did the same thing and eveything turned out fine, so do relax and just wait to see what your doctor says.
You do not have to lighten your weights at this point unless you feel discomfort in your joints or your heart rate spikes from using a heavier weight. The modifications that you should be aware of regarding weight training during pregnancy are as follows:
The main concern is to not be flat on your back after 12 weeks and to be aware that a hormone relaxin in now in your body. Relaxin naturally softens the bones, ligaments, and joints to prepare your body for child birth. Many experience the effects of this much more than others. In any case, as long as this hormone is present in your body, you should not be pushing your self to do extreme weight because your support system is not what is usually is. I kept doing my usual weight until suddenly one day I started to just feel that my usual weight was a struggle and/or I would feel unusual pulls or clicking sounds in my body while doing a certain exercise. All flat back exercises such as bench press, crunches, etc. should be done on an incline after 12 weeks as to not reduce the circulation that goes to the baby. Other exercises should always be done with caution and your body should always be supported. For instance if you are leaning over to do tricep kickbacks, have one arm (and possibly even your leg too) up on a bench to support your weight and give you back support. Exercises such as planks, leg raises, and push ups should be done at your discretion. I would STRONGLY suggest the modified bent knee versions of planks and push ups because they are very demanding poses to your lower back. Eventually when your belly gets very big you yourself will come to the realization that these exercises are simply not doable anymore. At that point, eliminate planks, if you haven't already, and do your ab work on all fours where you will have the baby weight to use as your resistance. Push ups can be done against the wall at this point. Long lever moves such as leg raises will most likely just be too uncomfortable due to balance issues and your pelvic area being very sensitive at this time. Remember, the relaxin in your body is softening your joints therefore weakening your support system to some degree.
Good Luck!