Took plan b on october 7th, started birth control (nortrel) on october 20th. any problems? also could starting bc make my period thicker?

No and No: It is not a problem to tart the pill after using plan b. In fact it is an excellent idea to use effective birth control rather than emergency b/c. Most women will have lighter periods when taking the pill, but it could take several cycle before you see a difference.

Good choice : A wise decision to start birth control and prevent an unplanned pregnancy. This will work better than emergency contraception. Over time your periods will likely be lighter.